🧾 Accounting & Business
The everyday arithmetic of running a business: margin and markup, sales tax, GST and VAT, break-even, depreciation, payroll and overtime, invoices and the key financial ratios. Formulas follow the free OpenStax Principles of Accounting textbooks and official guidance from agencies such as the IRS, ATO, HMRC and U.S. Department of Labor. These are general calculations, not tax advice.
30 free accounting & business calculators
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.