How to calculate hours worked
- Write down the start and finish time for each day, using a 24 hour clock if you can (1:30 pm is 13:30).
- Subtract the start from the finish. 13:30 minus 8:00 is 5 hours 30 minutes. If the shift goes past midnight, add 24 hours to the finish time first.
- Take off unpaid breaks. Short rest breaks of 5 to 20 minutes are normally paid under federal rules, so only take off genuine unpaid meal breaks.
- Convert to decimal hours by dividing the minutes by 60, then add up the week.
- Work out overtime. Federal law requires time and a half for hours over 40 in a week, and some states add daily overtime.
Minutes to decimal hours
| Minutes | Decimal | Minutes | Decimal |
|---|---|---|---|
| 5 | 0.08 | 35 | 0.58 |
| 10 | 0.17 | 40 | 0.67 |
| 15 | 0.25 | 45 | 0.75 |
| 20 | 0.33 | 50 | 0.83 |
| 25 | 0.42 | 55 | 0.92 |
| 30 | 0.50 | 60 | 1.00 |
Overtime rules in the US
The federal Fair Labor Standards Act (FLSA) requires non exempt employees to be paid at least one and a half times their regular rate for every hour over 40 in a workweek. There is no federal daily overtime, but a few states have their own. California requires overtime after 8 hours in a day and double time after 12, and Alaska, Nevada and Colorado also have daily rules. Use the California preset or set your own thresholds above, and always check the rules for your state.
Frequently asked questions
How do I calculate hours worked on a time card?
Subtract the start time from the end time, take off any unpaid breaks, then add up each day. For example 9:00 am to 5:30 pm is 8 hours 30 minutes, less a 30 minute unpaid lunch is 8 hours. Five of those days is 40 hours.
How do I convert minutes to decimal hours?
Divide the minutes by 60. 15 minutes is 0.25 hours, 30 minutes is 0.5 and 45 minutes is 0.75, so 7 hours 45 minutes is 7.75 hours. Payroll is usually entered in decimal hours.
When does overtime start?
Under the federal Fair Labor Standards Act, non exempt employees must be paid at least time and a half for hours over 40 in a workweek. Some states add daily overtime too. California, for example, requires overtime after 8 hours in a day and double time after 12.
Does the calculator work for overnight shifts?
Yes. If the end time is earlier than the start time, the shift is treated as finishing the next day, so 10:00 pm to 6:00 am counts as 8 hours.
Is time clock rounding legal?
Under federal rules, rounding to the nearest 5 minutes, tenth of an hour or quarter hour is allowed if it is neutral over time, so it does not always favour the employer. Some states, including California, are much stricter.
This calculator is a guide only and is not legal or payroll advice. It does not cover every rule, such as California's seventh consecutive day overtime.