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Converters, construction materials, cost estimates, accounting and engineering. Simple, instant, no sign-up.

Unit Converters

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Angle ConverterConvert degrees, radians, gradians (gons), turns, arcminutes and arcseconds, plus degrees-minutes-seconds (DMS).Area ConverterConvert square feet, square meters, acres, hectares, square yards, square miles and more. Exact factors from NIST.Cooking Measurement ConverterConvert cups, tablespoons, teaspoons, fluid ounces and mL, and estimate grams for flour, sugar, butter and more.Data Storage ConverterConvert bytes, KB, MB, GB, TB and binary KiB, MiB, GiB (plus TiB and bits). See why a 1 TB drive shows as about 931 GiB.Density ConverterConvert density between kg/m³, g/cm³, lb/ft³, lb/gal, tonnes/m³ and tons/yd³, with specific gravity.Energy ConverterConvert joules, kilojoules, calories, kilocalories (food Calories), kWh, Wh, BTU, foot-pounds and electronvolts.Force ConverterConvert force between newtons, kilonewtons, pound-force, kips, kilogram-force, dynes and poundals using exact NIST factors.Fraction to Decimal ConverterConvert fractions and mixed numbers to decimals and percentages, or decimals to simplified fractions and nearest 1/16 or 1/64.Fuel Economy ConverterConvert fuel economy between mpg (US), mpg (UK), L/100 km and km/L. Handles the inverse L/100 km scale correctly.Height Converter (Feet and Inches to cm)Convert height in feet and inches to centimeters and meters, or centimeters back to feet and inches (e.g. 5 ft 10 in).Length ConverterConvert between millimeters, centimeters, meters, kilometers, inches, feet, yards, miles and nautical miles instantly, using exact factors.Power ConverterConvert watts, kilowatts, horsepower (mechanical and metric), BTU per hour and tons of refrigeration.Pressure ConverterConvert psi, bar, kPa, pascals, atmospheres, mmHg, torr and inches of mercury (inHg) using NIST factors.Speed ConverterConvert mph, km/h, meters per second, feet per second and knots. Exact factors based on the international mile and foot.Temperature ConverterConvert Celsius to Fahrenheit, Fahrenheit to Celsius and either to Kelvin (plus Rankine) instantly, with the exact formulas explained.Time ConverterConvert between milliseconds, seconds, minutes, hours, days, weeks and years, with a days-hours-minutes breakdown.Volume ConverterConvert liters, gallons (US and UK), cubic feet, cubic meters, cubic yards, quarts, cups and milliliters instantly.Weight ConverterConvert kilograms, pounds, ounces, grams, stone and tons (mass). Also shows pounds + ounces and stones + pounds.

Area, Perimeter & Volume Calculators

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Annulus (Ring) Area CalculatorFind the area of a ring (annulus) between two circles, plus ring width and both circumferences, from inner and outer radius.Box Volume CalculatorVolume, surface area and space diagonal of a box or rectangular prism, in cubic feet, cubic meters, liters or gallons.Capsule Volume CalculatorVolume and surface area of a capsule (a cylinder with hemispherical ends), such as a propane tank or pill, from its radius and overall length.Circle CalculatorCalculate a circle’s area, circumference, diameter and radius from any one of radius, diameter or circumference.Cone CalculatorVolume, slant height, lateral and total surface area of a right circular cone from its base radius and height.Cylinder Volume CalculatorVolume and surface area of a cylinder from radius or diameter and height, in cubic feet, liters or gallons.Ellipse CalculatorCalculate the area, exact perimeter (circumference), eccentricity and focal distance of an ellipse or oval from its semi-axes.Frustum (Truncated Cone) CalculatorVolume, slant height and surface area of a conical frustum (truncated cone) such as a bucket, planter or lampshade, from both radii and the height.Pyramid Volume CalculatorVolume and surface area of a right rectangular or square pyramid from base length, base width and height.Rectangle CalculatorFind the area, perimeter and diagonal of a rectangle or square from its length and width, in any units.Regular Polygon CalculatorArea, perimeter, apothem, circumradius and interior angle of a regular polygon (pentagon, hexagon, octagon…) from side length.Right Triangle & Pythagorean Theorem CalculatorSolve a right triangle with the Pythagorean theorem: find the hypotenuse or missing leg, both angles, area and perimeter.Sector Area & Arc Length CalculatorArea, arc length, chord and perimeter of a circular sector (pie slice) from its radius and central angle or arc length, plus the segment area.Slope CalculatorTurn rise and run into slope percent (grade), angle in degrees, 1:x ratio, pitch per 12 and slope length.Sphere CalculatorVolume, surface area, diameter and circumference of a sphere or ball from its radius, diameter or circumference.Square Footage CalculatorCalculate square footage of rooms, floors and yards. Add up to three areas (rectangle, circle or triangle) and get ft², m², yd² and cost.Tank Volume CalculatorTotal and filled volume of vertical cylinder, horizontal cylinder or rectangular tanks in gallons and liters from liquid depth.Torus CalculatorVolume and surface area of a torus (ring or doughnut shape) from its major and minor radii, plus its inner and outer diameters.Trapezoid Area CalculatorFind the area of a trapezoid from its two parallel sides and height, plus the median and isosceles leg and perimeter.Triangle CalculatorEnter three sides to get a triangle’s area (Heron’s formula), perimeter, all three angles and its type.

Construction Materials Calculators

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Asphalt CalculatorHow many tons of hot mix asphalt you need for a driveway or lot: area × compacted thickness × density, with waste and price per ton.Board Feet CalculatorBoard feet for any lumber order: thickness × width × length ÷ 12 per piece, times quantity, with price per board foot.Brick CalculatorHow many bricks you need for a wall (modular, Norman, utility and more) with mortar joints, openings and waste, plus mortar and cost.Concrete Block CalculatorHow many 8×8×16 concrete blocks (CMU / cinder blocks) and bags of mortar you need for a wall, minus openings, with waste and cost.Concrete Column CalculatorConcrete for round (Sonotube) or square columns, piers and post holes: cubic yards, cubic meters, bags and cost for any number of columns.Concrete Footing CalculatorEstimate concrete for a continuous strip (wall) footing in cubic yards, cubic meters or 40/60/80 lb bags, with waste and cost.Concrete Mix Ratio CalculatorCement bags, sand, gravel and water to site-mix a volume of concrete at 1:2:3, 1:2:4 or 1:3:3, using the 1.54 dry-volume factor.Concrete Slab CalculatorHow much concrete for a slab, patio or driveway: cubic yards, cubic meters and 40/60/80 lb bags, with waste and ready-mix cost.Concrete Stairs CalculatorHow much concrete for solid poured steps: enter number of steps, rise, run, width and landing to get cubic yards, bags and cost.Cubic Yard CalculatorCubic yards (plus cubic feet and cubic meters) for a rectangular or round area at any depth, with optional waste and price per yard.Deck Boards CalculatorHow many deck boards, linear feet and screws you need for a rectangular deck, from board width, gap, board length and joist spacing.Drywall CalculatorHow many 4×8, 4×10 or 4×12 drywall sheets you need for a room’s walls and ceiling, minus doors and windows, with waste and cost.Excavation CalculatorDig volume for a pit, basement or trench in bank cubic yards, loose volume after swell, and how many dump-truck loads to haul it away.Fence CalculatorPosts, rails and pickets for a straight wood fence run from its length, post spacing and picket width and gap, with waste and total cost.Gravel CalculatorHow many tons and cubic yards of gravel or crushed stone you need for a driveway, path or base, with editable density and price per ton.Insulation CalculatorInsulation thickness to reach a target R-value with loose-fill or any product, or how many batt packages and layers you need.Mulch CalculatorHow much mulch you need in cubic yards or 2 ft³ / 3 ft³ bags for any bed size and depth, with bulk vs bagged cost.Paint CalculatorHow many gallons or liters of paint for a room: wall area minus doors and windows, optional ceiling, number of coats and coverage rate.Paver CalculatorPavers for a patio, walk or driveway including joint gap and waste, plus compacted gravel base and bedding sand volumes.Rebar CalculatorRebar for a slab grid: number of bars each way, total length, stock bars to buy and weight for #3–#6 bar at your spacing and edge cover.Retaining Wall Block CalculatorSegmental retaining wall blocks, cap units, drainage gravel and leveling pad stone for a wall of any length and height.Roof Pitch & Rafter Length CalculatorRoof pitch (x/12), angle and ridge rise from a building span, plus common rafter length including the eave overhang and ridge board.Roofing CalculatorTurn a house footprint and roof pitch into roof area, roofing squares and bundles of asphalt shingles (3 per square), with waste and cost.Sand CalculatorHow much sand you need in tons and cubic yards for paver bedding, a sandbox or fill, with editable density, waste and price.Stair Stringer CalculatorTurn total rise into the number of risers, riser height, tread run, stringer length and stair angle, checked against IRC riser and tread limits.Tile CalculatorHow many tiles and boxes you need for a floor or wall, allowing for grout joint width and cutting waste, plus cost per box.Tile Grout CalculatorHow much tile grout you need, in pounds, kilograms and bags, from the tiled area, tile size and thickness, and joint width.Topsoil CalculatorHow much topsoil or garden soil you need in cubic yards, bags and tons for a lawn, raised bed or garden, with waste and cost.Wallpaper CalculatorHow many rolls of wallpaper to buy, counted strip by strip from wall width, height, roll size, trim allowance and pattern repeat.

Price Estimators

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Appliance Electricity Cost CalculatorWhat an appliance costs to run: watts × hours of use × your electricity rate, per day, month and year, with optional standby power.Asphalt Paving Cost EstimatorEstimate an asphalt driveway or lot: tons of hot mix from area, thickness and density, priced with your $/ton, labor, mobilization, markup and tax.Concrete Job Cost EstimatorPrice a concrete slab, patio or driveway job with your own rates: ready-mix per yd³, delivery, labor and finishing per ft², markup and tax.Deck Building Cost EstimatorQuote a deck with your own prices: decking per ft² plus waste, framing and footings, railing per foot, stairs, labor, permit, markup and tax.Drywall Job Cost EstimatorEstimate a drywall job: sheets from wall and ceiling area plus waste, your sheet price, mud/tape supplies, hang-and-finish labor, markup and tax.Fence Cost EstimatorPrice a fence job with your own rates: material and labor per linear foot, gates, old-fence removal, markup and tax, plus cost per foot.Flooring Cost EstimatorEstimate a flooring job with your own prices: material per ft² plus waste, underlayment, installation labor, old-floor removal, markup and tax.Hourly Job Quote CalculatorBuild a quote for any trade: crew hours × your hourly rate, plus materials, equipment, travel, markup and sales tax, with a line-item breakdown.Landscaping Material Cost EstimatorPrice mulch, gravel or topsoil jobs: cubic yards from area and depth, your bulk price per yd³, delivery, spreading labor, markup and tax.Mileage Cost CalculatorWork out what a drive really costs: fuel from distance and fuel economy, a per-mile wear rate and tolls, compared with the IRS standard mileage rate.Moving Cost EstimatorEstimate a local move: movers × hours × hourly rate, truck rental and mileage, fuel, packing materials, valuation coverage, markup and tax.Painting Job Cost EstimatorQuote a painting job: gallons from wall area, coats and coverage, labor hours from your production rate, plus supplies, markup and sales tax.Pressure Washing Quote CalculatorQuote pressure washing by area: hours from your cleaning rate, labor, machine cost per hour, water use, cleaning chemicals, travel, markup and tax.Roofing Cost EstimatorPrice a re-roof by the square with your rates: shingles and underlayment, tear-off per layer, install labor, disposal, markup and sales tax.Sod / Turf Installation Cost EstimatorPrice a new lawn from sod: square feet plus waste, pallets, your sod price, soil prep, laying labor, old-lawn removal, delivery, markup and tax.Solar Panel Payback CalculatorEstimate how many years solar panels take to pay for themselves from system cost, incentives, yearly kWh produced and your electricity rate.

Accounting & Business Calculators

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Accounts Receivable Turnover CalculatorAccounts receivable turnover ratio and days sales outstanding (DSO) from net credit sales and beginning and ending receivables.Break-Even CalculatorFind how many units you must sell to cover fixed costs, the break-even sales revenue and your contribution margin ratio.CAGR Calculator (Compound Annual Growth Rate)Calculate the compound annual growth rate (CAGR) between a beginning and ending value over any number of years.Commission CalculatorWork out sales commission at a flat rate or with up to three tiers, plus total pay including an optional base salary.Contribution Margin CalculatorCalculate contribution margin per unit, contribution margin ratio and total contribution margin from price, variable cost and units.Cost of Goods Sold (COGS) CalculatorCalculate cost of goods sold from beginning inventory, purchases and ending inventory (periodic inventory method).Current Ratio CalculatorCurrent ratio, quick (acid-test) ratio and working capital from a balance sheet’s current assets, inventory and current liabilities.Depreciation CalculatorStraight-line, double-declining-balance or sum-of-the-years’-digits depreciation: a year’s expense, accumulated depreciation and book value.Discount CalculatorWork out the sale price and savings for a percentage discount, including a second stacked discount and the true combined discount.Gross Profit CalculatorCalculate gross profit (revenue minus cost of goods sold) and gross margin percentage for a product, period or business.GST Calculator (Australia & NZ)Add GST to a price or remove GST from a GST-inclusive price. Defaults to Australia’s 10% (one-eleventh); use 15% for New Zealand.Hourly to Salary CalculatorConvert an hourly wage to annual, monthly and weekly pay, or a salary back to an hourly rate, using your hours per week and weeks per year.Inventory Turnover CalculatorInventory turnover ratio and days’ sales in inventory from cost of goods sold and beginning and ending inventory.Invoice CalculatorTotal up an invoice: up to three line items (quantity × unit price), a discount, and sales tax or VAT on the discounted subtotal.Invoice Due Date CalculatorFind the payment due date for an invoice from its date and payment terms such as Net 30, Net 60 or EOM.IRR Calculator (Internal Rate of Return)Find the internal rate of return (IRR) of an investment from its upfront cost and up to six yearly cash flows.Labor Cost Calculator (True Cost of an Employee)Estimate the true hourly and annual cost of an employee: wages plus employer payroll taxes, insurance and benefits (labor burden).Late Payment Interest CalculatorCalculate simple interest on an overdue invoice from the amount, annual or monthly rate and days late, plus any flat late fee.Margin CalculatorFind gross margin % and profit from cost and selling price, or the price you need to hit a target margin.Margin vs Markup ConverterConvert a markup percentage to the equivalent gross margin, or a margin to the markup you need to apply to cost.Markup CalculatorAdd a markup percentage to your cost to get the selling price, markup amount and the equivalent gross margin.Net Profit Margin CalculatorEnter revenue, cost of goods sold, operating expenses, interest and tax to get gross, operating and net profit margins.NPV Calculator (Net Present Value)Discount up to six yearly cash flows at your required rate to get net present value (NPV) and the profitability index.Payback Period CalculatorFind how many years it takes for an investment to pay for itself, from even annual cash inflows or uneven year-by-year flows.Payroll Hours & Overtime CalculatorGross pay for a workweek from regular hours, overtime hours and hourly rate, with overtime at 1.5× as under the U.S. FLSA.Percentage Change CalculatorPercentage increase or decrease between two periods, the absolute change, and the average compound growth rate per period.Price Increase CalculatorFind the percentage increase between an old and new price, or apply a percentage increase to a price to get the new price.ROI CalculatorReturn on investment from what you put in and what you got back, plus the annualized ROI (compound annual growth rate) over the holding period.Sales Tax CalculatorAdd sales tax to a price, or work backwards from a tax-inclusive total to the pre-tax price and the tax included.VAT CalculatorAdd VAT to a net price or remove VAT from a gross, VAT-inclusive price. Defaults to the UK 20% standard rate (2026); any rate can be entered.

Engineering Calculators

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Battery Runtime CalculatorHow long a battery lasts from its amp-hour rating and load in amps or watts, with usable depth of discharge, inverter efficiency and Peukert correction.Beam Deflection CalculatorMaximum deflection, bending moment and reactions of a simply supported beam under a uniform or center point load, with an L/360 check.Bending Stress CalculatorMaximum bending stress σ = M·c/I = M/S in a beam for a rectangle, round bar, tube or any section, with section modulus and utilization.Bolt Torque CalculatorTightening torque for a target bolt preload with the short-form formula T = K·D·F, using nut factors from NASA’s Fastener Design Manual.CFM and Air Changes per Hour CalculatorConvert between airflow (CFM, m³/h or L/s) and air changes per hour (ACH) for a room, plus time to clear 99% of airborne contaminants.Column Buckling Calculator (Euler)Euler critical buckling load of a slender column for pinned, fixed or free ends, with slenderness ratio and critical stress.Gear Ratio CalculatorGear ratio from tooth counts for one or two stages, with output speed and output torque including efficiency.Heat Loss Calculator (U-value / R-value)Conductive heat loss through a wall, roof or window from area, temperature difference and U-value or R-value (US or SI).Hydrostatic Pressure CalculatorPressure at depth in a liquid with P = ρgh: gauge and absolute pressure for water, seawater or any fluid density.LED Resistor CalculatorCurrent-limiting resistor for one LED or a series string: exact ohms, nearest standard E12/E24 value, actual current and resistor wattage.Manning’s Equation Calculator (Open Channel Flow)Open-channel velocity and discharge with Manning’s equation for rectangular, trapezoidal, triangular and part-full circular sections.Moment of Inertia CalculatorSecond moment of area, section modulus and radius of gyration for rectangles, solid round bars, pipes/tubes and I-beams.Pipe Flow Rate CalculatorFlow rate from pipe diameter and velocity (Q = A·v), or the inside diameter needed to carry a flow at a target velocity.Pipe Pressure Drop CalculatorFriction pressure drop and head loss in a straight pipe using Darcy–Weisbach with the Swamee–Jain friction factor and a pipe roughness table.Power Factor Correction CalculatorCapacitor kVAR and microfarads needed to raise a load’s power factor to a target, with line current and kVA before and after correction.Pump Power CalculatorHydraulic (water) power, pump shaft (brake) power and motor input power from flow rate, total head, specific gravity and efficiency.RC and RL Time Constant CalculatorTime constant τ = RC or L/R, 5τ settling time, cutoff frequency and the percentage charged or discharged after any elapsed time.Reynolds Number CalculatorReynolds number for pipe flow from velocity, diameter, density and viscosity, with laminar, transitional or turbulent regime.Room AC BTU CalculatorRoom air conditioner size in BTU/h from floor area using the ENERGY STAR sizing chart, adjusted for sun, shade, occupants and kitchens.Shaft Torsion CalculatorMaximum shear stress (τ = T·r/J) and angle of twist (θ = TL/GJ) in a solid or hollow circular shaft under torque.Stress and Strain CalculatorCalculate axial stress, strain and Young’s modulus from force, cross-sectional area, original length and change in length.Thermal Expansion CalculatorChange in length (ΔL = αLΔT) of steel, aluminum, copper, concrete, glass and more for a temperature change, plus area and volume expansion.Three-Phase Power CalculatorReal power (kW), apparent power (kVA) and reactive power (kVAR) of a balanced three-phase load from line voltage, current and power factor.Torque, Power and RPM CalculatorConvert between shaft torque, speed and power with P = τ·ω, in N·m or lbf·ft, rpm or rad/s, kW or horsepower.Transformer Full-Load Current CalculatorPrimary and secondary full-load amps for a single-phase or three-phase transformer from its kVA rating and voltages, plus the turns ratio.Voltage Drop CalculatorVoltage drop and percent drop for copper or aluminum conductors by AWG/kcmil size, length and current, single-phase or three-phase.

Everyday Calculators

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Add or Subtract Days CalculatorAdd or subtract days, business days (Mon–Fri), weeks, months or years from a date to find the resulting date and weekday.Age CalculatorCalculate exact age in years, months and days from a date of birth, plus total days lived and days to the next birthday.Average Calculator (Mean, Median, Mode)Find the mean, median, mode, range and sum of up to 8 numbers, with each step shown.BMI Calculator (Adults)Calculate body mass index from height and weight in metric or US units, with the CDC adult weight category.BMR & Calorie CalculatorEstimate basal metabolic rate (Mifflin–St Jeor) and daily calories to maintain weight from sex, age, height, weight and activity level.Date Difference CalculatorCount the days between two dates, plus weeks and business days (Monday to Friday, excluding weekends).Days Until CalculatorCount down the days, weeks and months until any date, such as Christmas, a birthday, a holiday or a deadline.Fuel Cost CalculatorEstimate the fuel used and cost of a trip from distance, fuel economy (mpg or L/100 km) and fuel price.GPA CalculatorCalculate your GPA on the 4.0 scale from up to 8 letter grades (with plus/minus) and credit hours, plus your new cumulative GPA.Grade Percentage CalculatorTurn points earned out of points possible into a percentage score and a letter grade on the standard 90/80/70/60 scale.Hours Worked CalculatorCalculate hours worked from start and end times minus unpaid breaks, including overnight shifts, plus weekly hours and pay.Percentage CalculatorFind X% of a number, what percent one number is of another, or the percentage increase or decrease between two values.Ratio CalculatorSolve a proportion A : B = C : D for the missing value, or simplify a ratio to its lowest terms.Rounding CalculatorRound a number to N decimal places or to the nearest multiple (0.05, 5, 100…) using half up, half even (banker’s), up or down.Running Pace CalculatorFind your running pace per kilometer and per mile from distance and time, or predict a finish time from a target pace.Scientific Notation CalculatorConvert numbers to scientific, E and engineering notation with optional significant figures, or expand scientific notation to a decimal.Split Bill CalculatorSplit a restaurant or group bill evenly: add tax and tip, divide by the number of people, and optionally round each share up.Time Duration CalculatorAdd or subtract hours and minutes, or find the time between a start and end time, in h:mm and decimal hours for timesheets.Tip CalculatorWork out the tip and total for a restaurant bill and split it evenly between any number of people.Unit Price CalculatorCompare two products by price per unit (per ounce, gram, liter or item) to see which is the better deal and by how much.

Finance Calculators

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Amortization Schedule CalculatorSee a loan’s monthly payment, total interest, remaining balance after any year, and how much interest and principal you pay in that year.Auto Loan CalculatorCar loan payment from vehicle price, down payment, trade-in, sales tax and fees: monthly payment, total interest and total cost.Compound Interest CalculatorSee how savings grow with compound interest and monthly contributions: future value, total contributions and interest earned.Credit Card Payoff CalculatorFind how many months it takes to pay off a credit card balance with a fixed monthly payment, and the total interest you will pay.Debt-to-Income (DTI) Ratio CalculatorCalculate your debt-to-income ratio (monthly debt payments ÷ gross monthly income) and housing ratio, as lenders do.Inflation CalculatorProject what an amount will cost in the future, and what it will be worth in today's money, at a steady annual inflation rate.Loan Payment CalculatorCalculate the fixed monthly payment, total interest and total cost of an amortized loan such as a car or personal loan.Mortgage Calculator (PITI)Estimate your monthly mortgage payment: principal and interest plus property tax, homeowners insurance and PMI.Retirement Savings CalculatorProject your retirement savings from current balance, monthly contributions and expected return, in future and today’s money.Savings Goal CalculatorFind how much you need to save each month to reach a savings goal by a target date, with interest compounded monthly.Simple Interest CalculatorCalculate simple interest I = P × r × t and the total amount repaid or earned on a loan or deposit.

Science Calculators

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Density, Mass & Volume CalculatorSolve ρ = m/V for density, mass or volume in g/cm³, kg/m³ or lb/ft³, grams or pounds, mL, liters or gallons, plus specific gravity.Dilution Calculator (C1V1 = C2V2)Solve the dilution equation C1V1 = C2V2 for any one unknown: starting or final concentration or volume.Electrical Power CalculatorFind power in watts from voltage, current or resistance (P = VI, I²R, V²/R), plus energy used in kWh and running cost.Force Calculator (Newton's Second Law)Solve Newton's second law F = ma for net force, mass or acceleration, with force in newtons, pound-force and kilogram-force.Half-Life CalculatorWork out how much of a radioactive isotope or decaying substance remains after a given time from its half-life.Ideal Gas Law CalculatorSolve PV = nRT for pressure, volume, moles or temperature of an ideal gas, in kPa, atm, bar, liters, °C, K and more.Kinematics (SUVAT) CalculatorConstant-acceleration motion: from initial velocity, acceleration and time, find final velocity and displacement.Kinetic & Potential Energy CalculatorCalculate kinetic energy (½mv²) and gravitational potential energy (mgh) of an object in joules and other units.Molarity CalculatorFind the molar concentration (mol/L) of a solution from the mass of solute, its molar mass and the solution volume.Ohm's Law CalculatorSolve Ohm's law V = I × R for voltage, current or resistance, and get the power dissipated in watts.Percent Error CalculatorCompare a measured (experimental) value with the accepted (true) value: percent error, absolute error and relative error.pH CalculatorConvert between pH, pOH, hydronium [H₃O⁺] and hydroxide [OH⁻] concentration, and see whether a solution is acidic or basic.Projectile Motion CalculatorFind the range, maximum height and time of flight of a projectile from its launch speed, angle and height (no air resistance).Series & Parallel Resistor CalculatorCombine up to four resistors in series or parallel to get the equivalent resistance in ohms.Specific Heat CalculatorSolve q = mcΔT for heat energy, specific heat capacity, mass or final temperature. Water, metals and more.Wave Speed, Frequency & Wavelength CalculatorSolve v = fλ for wave speed, frequency or wavelength, and get the period. Works for sound, water and string waves.

Why SortedSums?

SortedSums is a free collection of 186 calculators for everyday life, the job site, the office and the lab. Every tool is one simple page: type your numbers and the answer updates instantly. There are no sign-ups and no downloads, and your numbers never leave your browser.

Results are estimates provided for informational and educational purposes only. Always verify important numbers with a qualified professional.