Decimal Hours Calculator
Convert hours and minutes to decimal hours so you can multiply by a pay rate. Enter 8 hours 30 minutes and you get 8.50 — divide the minutes by 60. The second box converts a decimal back to hours and minutes.
Why payroll uses decimal hours
A clock reads time as hours and minutes — 8:30. Payroll and billing store it as a decimal — 8.50 — because you can multiply a decimal straight by a rate. At $20 an hour, 8.50 × $20 = $170. Try that with 8:30 and the math breaks, which is the whole reason timesheets convert to decimals before they pay anyone.
The rule is one line: divide the minutes by 60. Thirty minutes is 30 ÷ 60 = 0.50. Fifteen is 0.25. Forty-five is 0.75. The whole hours stay as they are — only the minutes turn into a fraction.
Going the other way, multiply the decimal part by 60. A timesheet that says 8.25 hours is 0.25 × 60 = 15 minutes, so 8 hours 15 minutes. Watch the common slip: 8.30 is not 8 hours 30 minutes — it is 8 hours 18 minutes, because 0.30 × 60 = 18.
Minutes-to-decimal chart
Every minute from 1 to 59 as a decimal of an hour, rounded to two places.
| Min | Dec | Min | Dec | Min | Dec | Min | Dec |
|---|---|---|---|---|---|---|---|
| 1 | 0.02 | 16 | 0.27 | 31 | 0.52 | 46 | 0.77 |
| 2 | 0.03 | 17 | 0.28 | 32 | 0.53 | 47 | 0.78 |
| 3 | 0.05 | 18 | 0.30 | 33 | 0.55 | 48 | 0.80 |
| 4 | 0.07 | 19 | 0.32 | 34 | 0.57 | 49 | 0.82 |
| 5 | 0.08 | 20 | 0.33 | 35 | 0.58 | 50 | 0.83 |
| 6 | 0.10 | 21 | 0.35 | 36 | 0.60 | 51 | 0.85 |
| 7 | 0.12 | 22 | 0.37 | 37 | 0.62 | 52 | 0.87 |
| 8 | 0.13 | 23 | 0.38 | 38 | 0.63 | 53 | 0.88 |
| 9 | 0.15 | 24 | 0.40 | 39 | 0.65 | 54 | 0.90 |
| 10 | 0.17 | 25 | 0.42 | 40 | 0.67 | 55 | 0.92 |
| 11 | 0.18 | 26 | 0.43 | 41 | 0.68 | 56 | 0.93 |
| 12 | 0.20 | 27 | 0.45 | 42 | 0.70 | 57 | 0.95 |
| 13 | 0.22 | 28 | 0.47 | 43 | 0.72 | 58 | 0.97 |
| 14 | 0.23 | 29 | 0.48 | 44 | 0.73 | 59 | 0.98 |
| 15 | 0.25 | 30 | 0.50 | 45 | 0.75 |
Frequently asked questions
Divide the minutes by 60 and add them to the hours. So 8 hours 30 minutes is 30 ÷ 60 = 0.50, which makes 8.50 decimal hours. The whole hours never change — only the minutes become a fraction.
15 minutes = 0.25, 30 minutes = 0.50, and 45 minutes = 0.75. These three are the ones worth memorizing because most shifts land on a quarter hour.
Multiply the decimal part by 60. For 8.25 hours, 0.25 × 60 = 15 minutes, so it is 8 hours 15 minutes. The reverse box above does this for you.
You can multiply decimal hours straight by a pay rate. 8.50 hours × $20 = $170. You cannot multiply 8:30 by $20 and get the right answer, which is why timesheets and payroll software store time as a decimal.
Yes. 8.5 (or 8.50) decimal hours means 8 hours plus half an hour, which is 30 minutes. A common mistake is reading 8.30 as 8 hours 30 minutes — it is actually 8 hours 18 minutes, because 0.30 × 60 = 18.