Free Tool
Working Hours Calculator
How many hours did that shift actually take — and how many of them were billable? Enter a start time, an end time and a break, and this calculator gives you the shift length, the weekly total and the billable-hours split.
Estimates and scenarios for planning purposes only — not financial advice. The results on this page are built from the numbers you enter. They are planning aids, not predictions, and not financial, tax or legal advice. Nothing you enter leaves your browser.
What this tool does
The calculator works in two steps. First it measures one shift: the time from start to end, minus the break. If the end time is earlier than the start time, it assumes an overnight shift and counts through midnight — so 22:00 to 06:00 is an 8-hour shift, not a negative one. Then it scales the shift up: multiply by the days worked each week, and apply your billable percentage to split billable from non-billable hours.
The second step is the one freelancers usually get wrong. A 40-hour week is not 40 billable hours: admin, quoting, learning and chasing invoices all take time. Entering your honest billable share — most freelancers land between 60% and 80% — shows what your week really earns.
Try it
Waiting. Enter a start and end time and press Calculate hours.
How it works
Shift length is end time minus start time, minus the break. If the end time is earlier than the start time, 24 hours are added first — that is the overnight-shift rule. Weekly hours are the shift length multiplied by the days worked per week. Billable hours are the weekly total multiplied by the billable share; the rest is non-billable.
Times are entered as hours and minutes (HH:MM, 24-hour clock). The calculator works in minutes throughout and only converts back to hours and minutes for display, so there is no rounding loss: a 17:30 finish minus a 09:00 start is exactly 510 minutes, minus a 30-minute break is 480 minutes, or 8 hours.
Assumptions and limitations
- Breaks are entered as a single total in minutes. If you take two 15-minute breaks, enter 30.
- The calculator does not apply overtime rules, public holidays or local working-time law — those vary by country and contract, and this tool does not model them.
- Billable share is your estimate. The calculator cannot tell you how much of your week is billable; only your time records can.
Worked example
Example: a freelancer works 09:00 to 17:30 with a 30-minute break, 5 days a week, and estimates 75% of hours are billable. Shift length: 8 hours 30 minutes minus 30 minutes = 8 hours. Weekly total: 8 × 5 = 40 hours. Billable: 40 × 75% = 30 hours per week; non-billable: 10 hours.
Frequently asked questions
How do overnight shifts work?
If the end time is earlier than the start time, the calculator adds 24 hours — so 22:00 to 06:00 counts as 8 hours. A shift where start and end are identical is treated as an error, not as a 24-hour shift.
What counts as billable time?
Time a client pays for directly: the work itself, and any meetings or revisions the client agreed to pay for. Admin, marketing, learning and chasing invoices are usually non-billable — that is why the billable share is almost always below 100%.
Can I use this for a whole month?
Multiply the weekly total by the number of weeks you work in the month. For a yearly figure, multiply the weekly total by the weeks you actually work — most freelancers use 48 to 50 weeks, allowing for holidays.
What time format should I use?
Hours and minutes on the 24-hour clock, as HH:MM — for example 09:00, 17:30 or 22:15. Seconds are not supported.
Why is my weekly total lower than I expected?
Usually the break, or the billable share. A 30-minute daily break removes 2.5 hours from a 5-day week, and a 75% billable share removes another 10 hours from a 40-hour week.