Time Calculator
Add or subtract any number of hours and minutes, or find the time between two clock times. You'll see the total as hours and minutes, as decimal hours and as minutes, with the sum written out so you can check it.
Updated October 8, 2026Built and maintained by Muhammad YounusNothing you type leaves your browser
If the end's earlier than the start, it's counted as the next day.
How does a time calculator work?
Time doesn't add like ordinary numbers, because an hour's 60 minutes, not 100. The calculator turns every value into minutes, adds or subtracts them, then turns the result back into hours and minutes. That's why you can't just type 2.45 + 1.30 into a phone calculator and trust the answer.
Adding 2:45 and 1:30 by hand
2:45 + 1:30 = 3 hours 75 minutes
75 minutes = 1 hour 15 minutes
Total = 4:15 (4.25 hours)
Minutes to decimal hours
Divide the minutes by 60. Here are the ones people look up most:
| Minutes | 5 | 10 | 15 | 20 | 30 | 40 | 45 | 50 |
|---|---|---|---|---|---|---|---|---|
| Decimal | 0.08 | 0.17 | 0.25 | 0.33 | 0.50 | 0.67 | 0.75 | 0.83 |
Time between two clock times
Pick the Time between tab and enter a start and an end. A shift from 9:00 PM to 6:00 AM crosses midnight, so the calculator adds 24 hours to the end before it subtracts, and you get 9 hours. If you're totaling a full week of shifts with breaks, the time card calculator's built for that.
Common mistakes
The big one's treating minutes like decimals. If you type 1.30 into an ordinary calculator, it'll read it as one and three tenths of an hour, which is 1:18, not 1:30. That's why you'll want to enter times with a colon here.
The second's forgetting to carry the hour. 45 minutes plus 30 minutes isn't 75 minutes you can leave hanging; it's 1:15. The calculator carries it for you, and it'll show you where it did.
Last, people subtract across midnight the wrong way round. If you started at 9:00 PM and finished at 6:00 AM, you didn't work minus 15 hours. You'll get 9 hours once a day's added, which is what the Time between tab does.
If you're adding a long list, don't worry about the order; addition doesn't care. And if you've made a typo, you'll see it straight away, because the sum's written out under the result.
Frequently asked questions
How do I add hours and minutes?
Add the minutes first, then turn every 60 minutes into an hour. 2:45 plus 1:30 is 3 hours and 75 minutes, and 75 minutes is 1:15, so the answer's 4:15.
How do I subtract time?
Borrow an hour when the minutes don't go. For 5:10 minus 2:45, turn 5:10 into 4:70, then 4:70 minus 2:45 is 2:25.
How do I find the time between two clock times?
Subtract the start from the end. If the end's earlier than the start, the span crosses midnight, so add 24 hours. 9:00 PM to 6:00 AM is 9 hours.
How do I turn minutes into decimal hours?
Divide the minutes by 60. 30 minutes is 0.5 hours and 45 minutes is 0.75, so 7:45 is 7.75 hours. Payroll usually wants it that way.
What's 90 minutes in hours?
It's 1 hour and 30 minutes, or 1.5 hours in decimal.