Estimated tax installment calculator
Estimate the amount of each installment to pay over the year based on your estimated annual tax, the number of scheduled payments, and the amounts already paid. The calculation runs entirely in your browser.
How it works
This tool spreads the balance of your estimated annual tax (total tax minus what has already been paid) across the number of remaining payments you specify. Each payment gets an equal amount, rounded to the cent, and the last payment absorbs any rounding difference so that the installments add up exactly to the balance due.
How do I estimate my annual tax before calculating?
The starting amount is usually the one given by the tax authority (your previous tax notice, an installment letter) or your own estimate based on your projected income for the current year. If your activity varies a lot from one quarter to the next, consider asking the tax authority to adjust your installments rather than relying solely on an equal split.
Why is the default number of payments 4?
In France, estimated installments (corporate income tax, certain professional contributions) are most often paid quarterly, i.e. 4 times a year. You can still change this number to simulate monthly, semiannual, or any other payment schedule.
This calculation is a simplified estimate performed entirely in your browser; no data is sent to a server. It does not replace the advice of an accountant or the tax authority, who remain the reference for the exact schedule and amount of your installments.