Decimal Hours Converter: hh:mm to Decimal and Back
Payroll software usually wants 7.75 where your time card says 7:45. These two converters translate in both directions and show the working, and the tables below cover the common values.
Hours and minutes to decimal hours
Turn 7 hours 45 minutes into 7.75 for payroll.
Hours and minutes to decimal hours ·
Enter your numbers above and the result appears here.
How this was calculated
Decimal hours to hours and minutes
Turn 7.75 back into 7:45.
Decimal hours to hours and minutes ·
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How this was calculated
The two formulas
Example, hh:mm to decimal: 7 hours 45 minutes. 45 ÷ 60 = 0.75, so the decimal is 7 + 0.75 = 7.75.
Example, decimal to hh:mm: 7.75 hours. The whole number is 7 hours; 0.75 × 60 = 45 minutes, so 7:45.
Worked examples with awkward minutes
8 hours 20 minutes
20 ÷ 60 = 0.3333…, so 8:20 is 8.3333… hours. Rounded to two places that is 8.33. At $24.00/hour the exact pay is 8.3333 × $24 = $200.00, while 8.33 × $24 = $199.92. The 8-cent difference is why some payroll systems keep three or four decimal places.
6 hours 10 minutes
10 ÷ 60 = 0.1667, so 6:10 is 6.17 hours (rounded). Going back: 0.17 × 60 = 10.2 minutes, which rounds to 10, so 6.17 converts back to 6:10.
Decimal to time: 37.4 hours
0.4 × 60 = 24 minutes, so 37.4 hours is 37:24, not 37:40. This is the mistake people make most often when they read the decimal part as minutes.
Quarter-hour and common conversions
| Minutes | Decimal hours | Rounded (2 places) |
|---|---|---|
| 0 min | 0.0000 | 0.00 |
| 5 min | 0.0833 | 0.08 |
| 10 min | 0.1667 | 0.17 |
| 15 min | 0.2500 | 0.25 |
| 20 min | 0.3333 | 0.33 |
| 25 min | 0.4167 | 0.42 |
| 30 min | 0.5000 | 0.50 |
| 35 min | 0.5833 | 0.58 |
| 40 min | 0.6667 | 0.67 |
| 45 min | 0.7500 | 0.75 |
| 50 min | 0.8333 | 0.83 |
| 55 min | 0.9167 | 0.92 |
The quarter-hour marks are the ones to memorise: 15 minutes = 0.25, 30 minutes = 0.50, 45 minutes = 0.75. The full 1-to-59 minute chart is on the minutes to decimal chart, and the hours chart index has a table for every hour from 1 to 12.
Why a time card is converted to decimals
Pay is hours multiplied by rate. Multiplying 7:45 by $18.00 is awkward; 7.75 × $18.00 = $139.50 is simple. Payroll systems, invoices and spreadsheets store decimals for that reason. Time clocks that round to the nearest 6 minutes use tenths of an hour (6 minutes = 0.1), which makes every entry an exact one-decimal number. See rounding for how that works.
Common mistakes when converting
- Reading the decimal as minutes. 7.30 hours is 7 hours 18 minutes, not 7:30.
- Truncating instead of rounding. 8:50 is 8.8333…; cutting it to 8.83 loses a fraction of a minute, while 8.8 loses 2 minutes.
- Rounding too early. Convert every day to decimals with several places, add them, and round the total once. Rounding each day to two places can drift by a minute or two over a week.
- Mixing formats on one card. A column of 7:45, 8.25 and 7:30 is a recipe for a wrong total.
Example: why rounding order matters
Five days of 8:20
Each 8:20 is 8.3333 hours. Five days: 41.6667 hours = 41.67 hours, or 41:40. If every day is rounded first to 8.33, five days is 41.65 hours, which is 41:39. A one-minute difference per week is small, but it is also a shortfall over a year of 52 weeks of 52 minutes.
Where decimal hours show up
You meet decimal hours in payroll exports, invoices, project trackers, spreadsheets and union pay schedules. A spreadsheet stores a duration as a fraction of a day, so 6:00 is 0.25 in a time-formatted cell; multiply by 24 to get decimal hours (0.25 × 24 = 6.00). If you copy a time like 7:45 into a spreadsheet and multiply it by the hourly rate directly, the answer will be wrong unless you first multiply the time by 24. The converters above avoid that trap by working in plain hours and minutes.
Rule of thumb for checking: if the minutes are under 30, the decimal should be under .50; if you see 7.45 where you expected 7:45, the decimal is wrong, because 7:45 is 7.75.
Frequently asked questions
How do you convert minutes to decimal hours?
Divide the minutes by 60. 45 minutes is 45 ÷ 60 = 0.75 hours.
How do I convert 7:45 to a decimal?
7 + 45/60 = 7.75.
What is 8.5 hours in hours and minutes?
8 hours and 30 minutes: 0.5 × 60 = 30.
Why is 0.30 hours not 30 minutes?
Because the decimal is a fraction of an hour. 0.30 hours is 0.30 × 60 = 18 minutes. 30 minutes is 0.50 hours.
How many decimal places should I use?
Follow your payroll system. Two places is common; for exact pay keep more places until the final rounding.