Time Calculator
Add up durations, subtract them, find the time between two clock times or convert units — without wrestling with base 60.
- Hours : minutes : seconds
- Add and subtract
- Unit converter
- Private
Leave a field empty for zero. Values above 59 are fine: 90 minutes counts as 1 hour 30.
If the end is earlier than the start, it is taken as the next day.
How to add and subtract time
Three modes for three jobs.
- 1
Choose a mode
“Add and subtract” for durations, “Between two times” for clock times, “Convert” for units.
- 2
Enter the values
Fill in hours, minutes and seconds row by row and pick + or −. Empty fields count as zero.
- 3
Read the total
The result appears as h:mm:ss, in words and as decimal hours, minutes and seconds.
Base 60 without the headache
For timesheets, recipes, workouts, travel and video editing.
Add and subtract rows
Stack up as many durations as you like and mix additions with subtractions.
Between two times
Start and end time give the elapsed time; an end before the start is treated as the next day.
Convert units
Turn 10,000 seconds or 2.75 hours into a readable duration and every other unit.
Decimal hours
See 7:30 as 7.5 hours — the format payroll and invoices need.
Automatic carry
Type 90 minutes or 125 seconds; the calculator carries them into hours and minutes.
Link to your calculation
Copy a link that reopens the calculator with your numbers filled in — handy for sharing or saving a scenario.
Made for phones
Large fields, the right keyboard for numbers and a layout that fits small screens.
Private by design
Everything is calculated in your browser. Your numbers are not sent to a server.
Why time arithmetic trips people up
Time uses base 60: 60 seconds make a minute and 60 minutes an hour. So 1:45 plus 0:30 is not 1:75 but 2:15 — whenever minutes or seconds reach 60, one unit is carried to the left. The reliable method is to convert everything to seconds, add or subtract, and convert back; that is exactly what this calculator does.
Decimal hours are a different notation, not a different time. 7 hours 30 minutes is 7.5 hours, because 30 minutes is half an hour; 7 hours 20 minutes is 7.33 hours, not 7.20. To convert, divide the minutes by 60. Payroll systems and invoices usually want decimal hours, while schedules use hours and minutes.
For the time between two clock times, subtract the start from the end. If the end is smaller — 22:00 to 06:00 — the period crosses midnight and 24 hours are added, giving 8 hours. Clock times do not know about dates or daylight-saving changes; for spans of several days, use a date calculator and add the hours.
Minutes as decimal hours
| Minutes | Decimal hours | Example |
|---|---|---|
| 6 | 0.1 | 2:06 = 2.1 h |
| 15 | 0.25 | 2:15 = 2.25 h |
| 20 | 0.33 | 2:20 = 2.33 h |
| 30 | 0.5 | 2:30 = 2.5 h |
| 45 | 0.75 | 2:45 = 2.75 h |
Tips
- Adding up a working week with breaks and overtime? The Hours Calculator is built for that.
- For days between dates or a date some weeks ahead, use the Date Calculator.
- Turn hours worked into pay with the Salary Calculator.
- Billing by the quarter hour? Round each entry first (7 minutes or less down, 8 or more up) and then add — rounding the total gives a different result.
Frequently asked questions
Can’t find your answer? Contact us — we reply quickly.
How do I add hours and minutes?
Add the minutes first; if the sum is 60 or more, subtract 60 and carry 1 to the hours. Example: 2:45 + 1:30 → 75 minutes = 1 hour 15 → 4:15.
How do I convert minutes to decimal hours?
Divide the minutes by 60. 45 minutes ÷ 60 = 0.75, so 3 hours 45 minutes is 3.75 hours.
How do I calculate the time between two clock times?
Subtract the start time from the end time. If the end is earlier than the start, add 24 hours — the calculator does this automatically for overnight periods.
Can I enter more than 59 minutes or seconds?
Yes. Values such as 90 minutes or 400 seconds are accepted and converted into hours, minutes and seconds in the result.
Can the result be negative?
Yes. If you subtract more than you add, the total is shown with a minus sign.
Are my numbers stored or sent anywhere?
No. The calculation runs in your browser. Your last inputs are remembered on your own device only, so the form is still filled in when you come back; use Reset to clear them.
More free calculators
Money, dates, maths, health and home projects — quick answers that are worked out in your browser.