Time to Decimal Calculator
Enter a time as h:mm or h:mm:ss, or use separate hours and minutes boxes, and get decimal hours rounded the way your payroll rounds. Under the result you can compare all five rounding modes side by side.
Example: 8:45 or 8:45:30. Hours can go above 24.
Convert exactly, then round the decimal to 2 places (7:20 → 7.33).
Decimal hours
8.75hours
8 h 45 min = 8.75 hours
| Rounding mode | Rounded time | Decimal hours |
|---|---|---|
| 2 decimal places | 8:45 | 8.75 |
| Exact (up to 4 decimals) | 8:45 | 8.75 |
| Nearest quarter hour | 8:45 | 8.75 |
| Nearest tenth of an hour (6-minute rule) | 8:48 | 8.8 |
| Nearest 5 minutes | 8:45 | 8.75 |
How it works
A time to decimal calculator turns hours and minutes into a single number of hours. Everything is converted to seconds, divided by 3,600, and then rounded with the rule you pick.
decimal = (hours × 3,600 + minutes × 60 + seconds) ÷ 3,600
Worked example: Convert 8:07 with quarter-hour rounding
- Exact value: 8 + 7 ÷ 60 = 8.1167 hours
- Seven minutes is under the 7.5-minute halfway point, so the time rounds down to 8:00
- 8:00 = 8.00 hours
8:07 = 8.00 with quarter-hour rounding, but 8.12 with plain 2-decimal rounding
Rounding modes compared
The same time can convert to different decimals depending on the rule. These rows are calculated with the same code as the calculator.
| Time | Exact | 2 decimals | Quarter hour | 6-minute | 5-minute |
|---|---|---|---|---|---|
| 6:50 | 6.8333 | 6.83 | 6.75 | 6.8 | 6.83 |
| 7:20 | 7.3333 | 7.33 | 7.25 | 7.3 | 7.33 |
| 8:07 | 8.1167 | 8.12 | 8.00 | 8.1 | 8.08 |
| 8:08 | 8.1333 | 8.13 | 8.25 | 8.1 | 8.17 |
| 8:45 | 8.75 | 8.75 | 8.75 | 8.8 | 8.75 |
| 8:58 | 8.9667 | 8.97 | 9.00 | 9.0 | 9.00 |
Frequently asked questions
How do you convert time to decimal?
Divide the minutes by 60 and add the hours; divide seconds by 3,600. So 7:20 is 7 + 20 ÷ 60 = 7.3333, which is 7.33 to two decimal places.
Which rounding mode should I choose?
Match the rule your employer or client uses. Use 2 decimals or exact for a precise conversion, quarter hour if your time clock rounds to 15 minutes, the 6-minute rule if you bill in tenths of an hour, and 5 minutes for clocks that round to 5. The calculator cannot know your policy, so check with payroll if unsure.
Why does 7:20 show 7.33 and not 7.20?
Twenty minutes is one third of an hour (0.3333), not twenty hundredths. A decimal hour is split into 100 parts of 36 seconds each, not into minutes.
Does it work for durations over 24 hours?
Yes. Hours can be any whole number up to 99,999, so 27:30 converts to 27.50 and 100:15 converts to 100.25.
What happens exactly halfway between two rounding steps?
Ties round up. For example 8:07:30 is exactly halfway between 8:00 and 8:15 and becomes 8:15 under quarter-hour rounding. 8:07:29 rounds down to 8:00.