To add hours and minutes, add the hours and the minutes separately, then turn every 60 minutes into one hour. 7:45 + 8:30 is 15 hours and 75 minutes, which is 16:15. This hours and minutes calculator does it for as many rows as you need, subtracts where you tell it to, and shows the total in hours and minutes, in decimal hours and in minutes.
How to use the calculator
- Type one time per row. Each row takes a duration or a span from one clock time to another:
| You type | The row counts |
|---|---|
| 7:45 | 7 hours 45 minutes |
| 7.5 | 7 hours 30 minutes (decimal hours) |
| 8 | 8 hours |
| 45 min or 45m | 45 minutes |
| 1h30 | 1 hour 30 minutes |
| 8-16:30 | 8:30, the span from 8:00 to 16:30 |
| 9am-5pm | 8:00 |
| 22-6 | 8:00, past midnight |
- Switch a row to minus with the plus button at its start. It turns into a minus, and that row is subtracted from the total. Click it again to add the row back.
- Add more rows with "Add a row". The cross at the end of a row removes it, and "Clear" starts again with three empty rows.
- Read the total on the right: hours and minutes in large type, then decimal hours, industrial minutes and the total in minutes. Next to each row you also see its own value in decimal hours.
When you leave a row, a duration is rewritten as hours and minutes, so 7.5 becomes 7:30. That is a quick check that the calculator read what you meant. A row it cannot read gets a red border and counts as zero.
Worked example: adding up a week of hours
A week of hours from a paper log, written in different ways, with a 45 minute break on Thursday that was never taken off:
| Row | You type | Counts as | Decimal |
|---|---|---|---|
| Mon | 7:45-16:15 | 8:30 | 8.50 |
| Tue | 8:30 | 8:30 | 8.50 |
| Wed | 6.25 | 6:15 | 6.25 |
| Thu | 9:10 | 9:10 | 9.17 |
| Fri | 7:50 | 7:50 | 7.83 |
| Break | minus 0:45 | -0:45 | -0.75 |
| Total | 39:30 | 39.50 |
The five days add up to 40:15. Minus the break, the total is 39:30, which is 2,370 minutes or 39.50 decimal hours.
How to add hours and minutes by hand
- Write the times under each other and add the minutes: 45 + 30 + 15 = 90.
- Add the hours: 7 + 8 + 6 = 21.
- Carry every full 60 minutes into the hours: 90 minutes is 1 hour 30 minutes, so 21:90 becomes 22:30.
So 7:45 + 8:30 + 6:15 = 22:30. The common slip is to treat the minutes as decimals and write 21.90, which is neither 21:90 nor 22:30.
How to subtract hours and minutes
Subtract the minutes first. If there are not enough, borrow one hour and add 60 minutes.
40:00 minus 37:35: 0 minutes is less than 35, so borrow one hour. 39 hours 60 minutes minus 37 hours 35 minutes is 2:25. That is how much is left of a 40 hour week after 37 hours 35 minutes.
When you take away more than you have, the result is negative: 7:30 minus 8:15 is -0:45, or -0.75 decimal hours. The calculator shows the minus sign instead of wrapping around the clock, which is what you want for a balance like "45 minutes short".
Mistakes the input formats can cause
- A dot means decimal hours. 7.30 is 7.3 hours, which is 7:18, not 7:30. Type 7:30 for 7 hours 30 minutes.
- A plain number means hours. 45 is 45 hours. For 45 minutes, type 45 min or 0:45.
- Spans read a plain number as the 24 hour clock. 9-5 is 9:00 to 5:00 the next morning, 20 hours. Write 9-17 or 9am-5pm for a day shift.
- Minutes over 59 are not read after a colon. 1:90 gets a red border. Type 90 min, or 1:30.
Totals over 24 hours and decimal hours
The total keeps counting in hours, so a week shows 39:30 or 52:15, never "2 days 4 hours 15 minutes". That is the form timesheets and payroll use.
Decimal hours are the minutes divided by 60, rounded to two places: 9:10 is 9.17. The hours and minutes total is always exact, and the decimal total is worked out from it once, so it never drifts from adding rounded values. For a chart of every minute from 1 to 60, see hours to decimal.
Industrial minutes split an hour into 100 parts instead of 60. They are used in some German payroll and production systems: 39:30 is 3,950 industrial minutes.
When another calculator fits better
- One shift with a start, an end and a break: the work hours calculator.
- A whole week of clock in and clock out times with lunch deduction and overtime: the time card calculator.
- Overtime and overtime pay: the overtime calculator.
FAQ
How do you add hours and minutes?
Add the hours, add the minutes, then carry each 60 minutes into one hour. 3:40 + 2:35 is 5 hours 75 minutes, which is 6:15.
What is 7:45 plus 8:30?
16:15. 45 + 30 = 75 minutes, which is 1 hour 15 minutes, and 7 + 8 + 1 = 16 hours.
How do you subtract hours and minutes?
Subtract the minutes, borrowing 60 minutes from the hours if needed, then subtract the hours. 10:15 minus 3:40 is 9:75 minus 3:40, which is 6:35.
Can I add a time span like 8 to 4:30?
Yes. Type it as 8-16:30 or 8am-4:30pm in one row and the row counts 8:30. Spans past midnight work too: 22-6 counts 8 hours.
How many hours is 90 minutes?
1 hour 30 minutes, or 1.5 hours. Type 90 min in a row to add it.
How do I add up hours and minutes in Excel or Google Sheets?
Enter each time as 7:45, add them with =SUM(), and format the result cell with the custom format [h]:mm. Without the square brackets, a total over 24 hours starts again from 0.
Does the calculator round the minutes?
No. Hours and minutes are added exactly. Only the decimal hours are rounded, to two places.