How to use the decimal hours calculator
- To turn a clock-style figure into decimals, type the hours and minutes into the hh:mm side, for example
7:45. - Read the decimal value that appears beside it. It updates as you type, so there is no button to press.
- To go the other direction, type a decimal number such as
6.4into the decimal side. - Read the hours and minutes it returns, in this case 6 hours 24 minutes.
- Use the minute chart further down the page when you only need to look up one value, such as what 37 minutes comes to.
- Copy whichever figure your timesheet or payroll form asks for.
Why payroll runs on decimals
A pay calculation is a multiplication, and minutes do not multiply cleanly. If someone works 7 hours 45 minutes at $22 an hour, you cannot type 7:45 into a spreadsheet cell and multiply. Converted to 7.75 the sum becomes obvious: 7.75 x 22 = $170.50. Every payroll system, accounting package and invoicing template therefore expects hours expressed as a plain number with a fraction, which is why timesheets so often carry two columns showing the same day twice.
The rule behind the conversion is one division: minutes divided by 60. Forty-five minutes is 45 / 60 = 0.75. Twenty minutes is 20 / 60 = 0.3333, usually written 0.33. The hours part never changes, so 7:45 becomes 7 + 0.75 = 7.75 and 3:20 becomes 3 + 0.33 = 3.33. Going the other way, take whatever sits after the decimal point and multiply by 60: the 0.4 in 6.4 is 0.4 x 60 = 24 minutes.
The mistake that costs money: 7.45 is not 7:45
Writing 7.45 when the shift was 7 hours 45 minutes is the single most common timesheet error. Read literally, 7.45 hours means 7 hours plus 0.45 x 60 = 27 minutes, so the two figures are 18 minutes apart. At $22 an hour the gap is 7.75 x 22 = $170.50 against 7.45 x 22 = $163.90, a shortfall of $6.60 on one day. Repeat that across ten shifts in a pay period and it is $66.
The tell is simple. A colon separates hours from minutes and anything after it runs from 00 to 59. A decimal point separates hours from a fraction of an hour and anything after it runs from 0 to 99. Whole hours are the only values that read identically in both systems, so 8:00 and 8.00 agree while almost nothing else does. One quick sanity test: a figure above .59 after the mark can only be decimal notation, because no clock ever shows 7:75.
Rounding, and how far to take it
Most minute values divide by 60 without ending. Ten minutes is 0.166666, fifty minutes is 0.833333. Two decimal places is the normal payroll convention and is accurate to within about 0.3 of a second, which is far tighter than any time clock. Three or four places do no harm in a spreadsheet but tend to be trimmed later anyway.
Where two places bite is when you round first and add second. Rounding each day then summing the column lets several small truncations stack up. The fix is to add the raw hours and minutes first and convert the single total, which is what the next section shows.
Worked example: converting a whole week
| Day | Worked | Decimal, two places |
|---|---|---|
| Monday | 7:45 | 7.75 |
| Tuesday | 8:20 | 8.33 |
| Wednesday | 6:50 | 6.83 |
| Thursday | 9:05 | 9.08 |
| Friday | 7:30 | 7.50 |
Add the decimal column: 7.75 + 8.33 = 16.08, plus 6.83 = 22.91, plus 9.08 = 31.99, plus 7.50 = 39.49 hours.
Now add the clock column instead. 7:45 + 8:20 = 16:05. Plus 6:50 = 22:55. Plus 9:05 = 32:00. Plus 7:30 = 39:30, which converts to 39 + 30 / 60 = 39.50 hours.
The two answers differ by 0.01 hours because Tuesday, Wednesday and Thursday were each shaved slightly when rounded to two places. At $20 an hour that is $789.80 against $790.00, a 20 cent difference from one week. Convert the total rather than the parts and the discrepancy disappears. Converting 39.50 back is easy to verify: 0.50 x 60 = 30, so 39 hours 30 minutes.
If you would rather not add clock times by hand, enter the in and out pairs on the timesheet calculator and it will produce both columns for you. For a single span, the hours calculator gives the same pair of figures.
Frequently asked questions
What is 7:45 in decimal hours?
7.75 hours. The minutes convert on their own: 45 / 60 = 0.75, which is added to the 7 whole hours. The same logic makes 7:15 into 7.25 and 7:30 into 7.5.
Why does 20 minutes become 0.33 instead of 0.20?
Because a third of an hour is 0.33, and twenty minutes is a third rather than a fifth. Dividing 20 by 60 gives 0.3333, which shortens to 0.33. Only the quarter-hour marks of 15, 30 and 45 minutes land on tidy decimals of 0.25, 0.5 and 0.75.
Is 7.5 hours the same as 7 hours 50 minutes?
No. 7.5 hours is 7 hours 30 minutes, since 0.5 x 60 = 30. Seven hours and fifty minutes converts to 7.83 hours. The confusion is worth watching for, because the two are 20 minutes apart.
How many decimal places should I keep?
Two is standard for payroll and matches what most systems store. Keep more only if you are building a spreadsheet that adds many days, and even then convert the total instead of adding rounded daily values.
How do I convert a whole week in one step?
Total the daily hours and minutes first, carrying every 60 minutes into an extra hour, then convert that single figure. A week totalling 41:20 becomes 41 + 20 / 60 = 41.33 hours.
What decimal is 10 minutes?
0.1667, normally written 0.17. Ten minutes recurs when divided by 60, so it never lands exactly. The full list from 1 to 60 minutes is on the minutes to decimal hours chart.
Do overtime hours convert the same way?
Yes. The conversion is arithmetic and does not care how the hours are classified. You convert first, then apply the rate, so 6 hours 30 minutes of overtime becomes 6.5 hours and is priced at the overtime rate on the overtime calculator.