Time Calculator guide
Time Calculator: Add and Subtract Hours and Minutes
Use our time calculator to add or subtract hours, minutes and seconds from a time of day, or to add up lengths of time.
By the AllCalculator editorial teamUpdated 16 October 20261 min read
If a film starts at 9:30 and lasts 3 hours 20 minutes, when does it finish? Our Time Calculator answers questions like this, and adds up lengths of time too.
How to use the calculator (Time Calculator)
Choose what to do:
- Add or subtract time from a time of day: enter the start time and the hours, minutes and seconds.
- Add or subtract two lengths of time: enter both durations.
How it works
Time doesn't work in tens: there are 60 seconds in a minute, 60 minutes in an hour and 24 hours in a day. The calculator handles the carrying for you, and tells you if the result goes past midnight.
Worked examples
- With the calculator's default settings, 09:30 + 3 hours 20 minutes = 12:50.
- 22:30 + 3 hours 45 minutes = 02:15 the next day.
- 2h 45m + 3h 20m = 6h 5m, or 6.08 decimal hours.
Decimal hours
Payroll and timesheets often use decimal hours. To convert, divide the minutes by 60:
| Hours and minutes | Decimal hours |
|---|---|
| 15 minutes | 0.25 |
| 30 minutes | 0.5 |
| 45 minutes | 0.75 |
| 7h 20m | 7.33 |
Frequently asked questions
How do I find the time between two times?
Use our Calculate Duration of Time calculator.
How do I add up a week of working hours?
Our Time Card Calculator totals each day's hours and works out your pay.
Sources and further reading
Links open official and independent websites in a new tab.
This guide is general information to help you understand your options. It isn't financial, tax, legal or building advice and doesn't take your personal circumstances into account. Figures were checked when the guide was last updated and can change, so confirm anything important with GOV.UK, HMRC, a regulated adviser or a qualified tradesperson.