Decimal Hours Explained: Why 7:30 Is 7.5 Hours on Your Payslip
Last updated · By the DropFlick team
Decimal hours express time as a fraction of an hour: 30 minutes is 0.5, 15 minutes is 0.25. Payroll and billing systems use them because you can multiply decimals by an hourly rate. You can't do that with hours and minutes.
Converting minutes to decimal hours
Decimal hours = hours + (minutes ÷ 60)
- 6 hours 12 minutes = 6 + 12 ÷ 60 = 6.2
- 8 hours 40 minutes = 8 + 40 ÷ 60 = 8.67 (8.6667 exactly)
- 38 hours 45 minutes = 38 + 45 ÷ 60 = 38.75
Converting decimal hours back
Minutes = decimal part × 60
- 7.3 hours = 7 hours + 0.3 × 60 = 7 hours 18 minutes
- 4.85 hours = 4 hours + 0.85 × 60 = 4 hours 51 minutes
Quick reference
| Minutes | Decimal | Minutes | Decimal |
|---|---|---|---|
| 5 | 0.08 | 35 | 0.58 |
| 10 | 0.17 | 40 | 0.67 |
| 15 | 0.25 | 45 | 0.75 |
| 20 | 0.33 | 50 | 0.83 |
| 25 | 0.42 | 55 | 0.92 |
| 30 | 0.50 | 60 | 1.00 |
The full 1–60 minute chart is on the converter page and prints on one sheet.
Why the difference matters
Suppose you worked 39 hours 50 minutes at $21/hour. Correctly converted, that's 39.83 × $21 = $836.43. If someone types 39.50 instead, the pay is $829.50, which is $6.93 short every week. Over a year that's more than $350. Always check that a payslip's hours are decimals of 60-minute hours.
Rounding decimal hours
Two decimal places (hundredths of an hour, 36 seconds each) are standard. Some systems use tenths of an hour (6-minute blocks), common in professional billing. If your employer rounds clock punches, see time clock rounding rules.