How to convert minutes to decimal hours
Divide the minutes by 60.
Decimal hours = minutes ÷ 60
45 minutes is 45 ÷ 60 = 0.75 hours. 135 minutes is 135 ÷ 60 = 2.25 hours. The same works for any number of minutes, so a long shift entered as 510 minutes becomes 8.5 hours.
If you have hours and minutes together, like 7 hours 45 minutes, the hours to decimal calculator takes both at once and has a full 1–60 minute chart.
Minutes to tenths of an hour
Many employers and almost all law firms, consultants and agencies record time in tenths of an hour, so every entry is a multiple of 6 minutes. Each time is rounded to the nearest 6 minutes:
| Minutes worked | Recorded as |
|---|---|
| 0–2 | 0.0 hours |
| 3–8 | 0.1 hours |
| 9–14 | 0.2 hours |
| 15–20 | 0.3 hours |
| 21–26 | 0.4 hours |
| 27–32 | 0.5 hours |
| 33–38 | 0.6 hours |
| 39–44 | 0.7 hours |
| 45–50 | 0.8 hours |
| 51–56 | 0.9 hours |
| 57–60 | 1.0 hours |
So a 20-minute call is billed as 0.3 hours and a 50-minute meeting as 0.8 hours. This calculator shows the tenth-of-an-hour value under every result.
Minutes to quarter hours
Payroll systems that round to 15 minutes usually follow the 7-minute rule: up to 7 minutes past a quarter rounds down, 8 or more rounds up.
| Minutes past the hour | Recorded as |
|---|---|
| 0–7 | .00 |
| 8–22 | .25 |
| 23–37 | .50 |
| 38–52 | .75 |
| 53–60 | next full hour |
Federal rules allow rounding to the nearest 5 minutes, tenth of an hour or quarter hour only if, over time, employees are paid for all the time they actually work. See 29 CFR 785.48. Rounding that always favors the employer is not allowed.
Common mistakes
Writing 45 minutes as .45
.45 hours is only 27 minutes. 45 minutes is .75 hours.
Rounding every entry, then rounding the total again
If you bill in tenths, round each entry once and add the rounded values. Rounding the total a second time changes the bill. If you pay exact time, add the exact minutes first and convert once.