Overtime pay: work out the gross and net amount

How it is calculated

The tool starts from the base gross hourly rate: the contract's monthly gross divided by the hours in the month (35 h a week × 52 ÷ 12, i.e. 151.67 h). Overtime entered per week is converted per month the same way. It then works out the premium hours: at the legal rate, 25% for the first 8 hours of each week and 50% beyond; with an agreed rate, that single rate on every hour. Hours plus premium, multiplied by the hourly rate, give the gross overtime pay.

The modele-social engine then recalculates the whole payslip with those hours: employee contributions apply, then the pension contribution relief specific to overtime is deducted. The net added is the difference between net pay with and without those hours, which accounts for threshold effects. If the contract is below the legal working time, the tool switches to additional hours, with the premium the engine applies to part-time work.

What the result includes

So that two people get the same figure from the same gross pay, the site always calculates from the same baseline situation. Each line can be changed in the calculator's options where it matters.

• General social security scheme (régime général), rates as of 26 October 2026 (rules from modele-social, the engine behind URSSAF's simulator).
• Permanent full-time contract (CDI), 35 hours a week, i.e. 151.67 h a month, paid over 12 months.
• Non-cadre by default (cadre status is one button away), collective agreement set to the general rules (“droit commun”).
• Company health cover (mutuelle) of €40 a month, of which €20 is deducted from pay, URSSAF's default setting; zero is possible in the options.
• Outside Alsace-Moselle (option available), without meal vouchers or benefits in kind.
• Before income tax: tax withheld at source depends on your household and comes on top (see the “net after tax” tool).
• Minimum wage (SMIC) since 1 June 2026: €12.31 gross per hour (service-public.gouv.fr).
• Employee contribution relief on overtime, included in the net figure; income tax exemption up to €7,500 net per year, mentioned but not calculated.
• Premium: legal bands or a single agreed rate (minimum 10%), since 1 January 2019 (service-public.gouv.fr).

Limits

A correct calculation for a typical situation is not your payslip. Here is what the tool does not know, so that you read the result as a reliable order of magnitude, not a promise.

• Collective agreement: sector minimums, seniority bonuses, compulsory thirteenth month and specific provident schemes are not taken into account (general rules only).
• Bonuses, variable pay, overtime, benefits in kind: left out, except in the tools that ask for them.
• Health cover and provident scheme: your actual contribution may be different; change it in the options.
• Alsace-Moselle: the option adds the local scheme's health contribution, without its other specifics.
• Public sector not covered: civil servants' pay scales and contributions follow other rules.
• Simplified tax: no tax reductions or credits, no exceptional income; the engine's “tax” module is flagged as experimental by URSSAF.
• Compensatory rest: hours paid as time off rather than money, and the compulsory rest beyond the annual quota, are not simulated.
• Day-based and hour-based “forfait” contracts: cadres on a forfait do not count overtime this way; the tool assumes hours are tracked.
• Employer flat-rate deduction and annual quota: on the employer and legal sides, mentioned in the text, not quantified in the result.

What overtime brings

For €3,000 gross a month at 35 h, non-cadre, legal premium: gross pay for the hours, contribution relief, net added and total net, calculated by the site's engine.

Annual quota and maximum hours

Without an agreement, the annual overtime quota is 220 hours per employee (service-public.gouv.fr); beyond it, each hour entitles you to compulsory rest on top of its premium. Working time cannot exceed 10 hours a day or 48 hours in a single week, barring exemptions. Those ceilings explain the limit of the “per week” field: 8 h at 25%, then up to 13 h in total.

Overtime is counted per calendar week, Monday to Sunday, unless working time is arranged over a longer period (annualised hours, cycles). In that case only the hours beyond the average over the period carry a premium, and the tool, which reasons on an average month, gives an order of magnitude rather than an exact payslip. The overtime guide explains how to read the lines of your payslip.

Overtime, a forfait or a pay rise?

If your overtime is regular, you have three ways of getting it paid: declare it and have it paid with a premium each month, ask for a longer contract with those hours built in, or negotiate a rise in base salary. The first is the most favourable in net terms thanks to the contribution relief and the tax exemption; the third counts more for your pension, unemployment benefit and end-of-contract payouts, which are calculated on base salary. The pay rise simulator gives the net of a rise in base gross pay; compare it with the net added by your hours.

To place your hourly rate, the hourly, monthly and annual converter and the SMIC guide give the benchmarks; part time, the part-time salary tool completes the calculation of additional hours.