How many hours have you actually worked this month? Between breaks, overtime and days with variable schedules, the calculation can quickly get complicated.
A working time calculator solves this problem in seconds: you enter your start and end times, and it automatically calculates your effective working time, your overtime hours and your break time.
In this guide: how to use a free calculator, the French legal rules on the 35-hour week and overtime pay, and the recommended tools for 2026.
Article updated on 25/06/2026
The basics of calculating working hours
Calculating working hours, whether it's actual effective working time or break periods, is a major issue for many companies and freelancers. It's about ensuring that employees are paid fairly. But it's also about being able to analyze productivity, estimate the profitability of a project, and organize resource allocation.
What is a calculator?
A working time calculator is a tool that allows you to record hours worked and automatically calculate the total working time over a given period. Its principle is simple: you record each start and end of activity, then the calculator adds up the hours, taking into account any breaks, travel time (when included), and overtime pay.
Why use a calculator?
- Accurately track working hours: time tracking, time entry, complete time transparency.
- Save time: instead of manually calculating the total hours, the tool automatically adds them up, including or excluding overtime hours as needed.
- Analyze productivity: by generating activity reports and automated reporting, you can identify time-consuming projects or activity peaks.
- Improve payroll management: the data collected can be exported as a CSV file, then easily integrated into payroll software.
- Complying with legislation: having a reliable record of hours worked is essential to prove compliance with working time regulations.
French labor law on working time
Some key legal benchmarks to interpret your calculations:
- Legal duration: 35 hours per week (1,607 hours per year) for full-time employees
- Overtime: increased by 25% from the 36th to the 43rd hour, then 50% beyond
- Maximum duration: 48 hours per week (60 hours in exceptional cases), 10 hours per day
- Mandatory break: 20 minutes minimum beyond 6 consecutive hours of work
- Record-keeping: the employer must retain time records for 5 years (article D.3171-16 of the Labor Code)
How do I fill out a working time calculator?
The steps
- Define the time range: enter the start time and end time of your day, including or excluding breaks.
- Identify the tasks or projects.
- Record overtime hours.
- Validate and review the reports.
- Perform the CSV export.
Here is an example of a free calculator
Working time calculation examples
- Standard week: 35h gross, 5h breaks (1h/day), 35h net, 0h overtime
- Busy week: 42h gross, 5h breaks (1h/day), 42h net, 7h overtime (25% premium)
- 80% part-time: 28h gross, 4h breaks (48min/day), 28h net, 0h overtime
- Shift hours: 38h gross, 3h30 breaks, 38h net, 3h overtime (25% premium)
How to read these examples: overtime hours start from the 36th weekly hour. The first 7 overtime hours (36th–43rd) are increased by 25%, the following ones by 50%.
Methods for calculating working hours
The Excel spreadsheet
Ease of customization, compatibility, graph generation.
The online calculator
Accessibility, advanced features, simplified collaboration.
Timesheet software
Time tracker, calculation module, HR integration, dashboard, activity reports.
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FAQ on the working time calculator
How do I calculate working hours?
To calculate your effective working time, subtract the start time from the end time, then deduct unpaid breaks. Example: arriving at 9:00 AM, leaving at 6:00 PM, 1-hour break = 8 hours of effective working time. For a week, add up the daily totals and compare to the 35-hour threshold to identify overtime hours.
Does the calculator take breaks into account?
Yes, a good working time calculator allows you to deduct breaks from the total time. Note: only unpaid breaks are deducted. Breaks of less than 20 minutes may be paid depending on your collective agreement.
How is overtime calculated?
Overtime hours are hours worked beyond 35 hours per week. The first 8 hours (36th to the 43rd hour) are increased by 25%, the following ones by 50%. They also benefit from a tax exemption up to 5,000 euros per year.
Is a collective agreement required for automated time tracking?
No, but the employer must precisely inform employees of the implementation of a monitoring system. The use of a time tracking system or automated working time calculator is free, subject to compliance with GDPR rules on personal data.
