Free online calculators
Work out a percentage, a rule of three or VAT, convert a gross salary to net, estimate a loan or compound interest, and convert units or currencies. Every calculator explains its result so you can check it yourself.
Everyday calculations
- CalculatorFree online calculator, standard and scientific: order of operations, trigonometric functions, history, memory and keyboard support.
- Percentage CalculatorFive percentage calculators: share, proportion, change, discount or increase, and initial value, with the detailed formula.
- Rule of Three CalculatorSolve a rule of three online: fill in 3 boxes and the 4th is calculated with cross multiplication explained step by step, for direct or inverse proportion.
- Unit ConverterConvert length, weight, temperature, volume, area and speed between metric and US/imperial units, with the formula.
Money, salary and loans
- VAT CalculatorAdd VAT to a net price or remove it from a gross price, with the VAT amount and the formula, at any rate.
- Gross to Net Salary CalculatorConvert a gross salary to net (or net to gross) per month, year and hour, with take-home pay after income tax withholding.
- French Income Tax CalculatorEstimate your French income tax for 2026 (2025 income) for free: tax shares, family quotient, décote, marginal rate and a bracket-by-bracket breakdown.
- Currency ConverterConvert dollars, euros, pounds, Swiss francs and more at the official European Central Bank reference rate, with a 90-day chart.
- Compound Interest CalculatorSee how your savings grow with compound interest: final balance, interest earned, and a year-by-year table and chart.
Real estate
- Mortgage CalculatorWork out your monthly mortgage payment, the total cost of the loan and how much you can borrow, with an amortization schedule, CSV export and printing.
- French Notary Fees CalculatorEstimate the notary fees when buying property in France: resale, new-build or land, with a breakdown of transfer taxes, notary charges and other costs.
Frequently Asked Questions
Are the results reliable?
The calculations follow official or standard formulas. For an important decision, such as a loan, treat them as an estimate and compare with your bank.
Are the exchange rates up to date?
Yes. The currency converter uses the reference rates published every business day by the European Central Bank.
Do I need to create an account?
No. All the calculators are free and ready to use right away, on desktop or on your phone.