To convert minutes to decimal hours, divide the minutes by 60. 15 minutes is 0.25 hours, 30 minutes is 0.5, 45 minutes is 0.75, and 20 minutes is 0.33 when rounded to two decimal places.
Payroll systems, invoices and project trackers often want time as a single decimal number, while clocks and timesheets give you hours and minutes. This guide gives you the formula both ways, a full chart from 1 to 60 minutes, the common rounding rules and the mistakes that cost people a few minutes on every timesheet. If you’d rather not do the arithmetic, the hours calculator shows every shift and weekly total in both formats.
The formula, both ways
- Minutes to decimal hours: decimal = minutes ÷ 60. For 7 hours 36 minutes, 36 ÷ 60 = 0.6, so the total is 7.6 hours.
- Decimal hours to minutes: minutes = decimal part × 60. For 5.4 hours, 0.4 × 60 = 24, so the total is 5 hours 24 minutes.
- Seconds too: divide seconds by 3,600. 1 hour 30 minutes 36 seconds is 1 + 30 ÷ 60 + 36 ÷ 3,600 = 1.51 hours.
The most common mistake is reading the decimal as minutes. 7.5 hours is 7 hours 30 minutes, not 7 hours 50 minutes, and 8 hours 45 minutes is 8.75, not 8.45.
Minutes to decimal hours chart (1 to 60)
Values are rounded to two decimal places, which is what most payroll systems use. Multiples of 3 minutes come out exact: 3, 6, 9, 12 and so on.
| Minutes | Hours | Minutes | Hours | Minutes | Hours |
|---|---|---|---|---|---|
| 1 | 0.02 | 21 | 0.35 | 41 | 0.68 |
| 2 | 0.03 | 22 | 0.37 | 42 | 0.70 |
| 3 | 0.05 | 23 | 0.38 | 43 | 0.72 |
| 4 | 0.07 | 24 | 0.40 | 44 | 0.73 |
| 5 | 0.08 | 25 | 0.42 | 45 | 0.75 |
| 6 | 0.10 | 26 | 0.43 | 46 | 0.77 |
| 7 | 0.12 | 27 | 0.45 | 47 | 0.78 |
| 8 | 0.13 | 28 | 0.47 | 48 | 0.80 |
| 9 | 0.15 | 29 | 0.48 | 49 | 0.82 |
| 10 | 0.17 | 30 | 0.50 | 50 | 0.83 |
| 11 | 0.18 | 31 | 0.52 | 51 | 0.85 |
| 12 | 0.20 | 32 | 0.53 | 52 | 0.87 |
| 13 | 0.22 | 33 | 0.55 | 53 | 0.88 |
| 14 | 0.23 | 34 | 0.57 | 54 | 0.90 |
| 15 | 0.25 | 35 | 0.58 | 55 | 0.92 |
| 16 | 0.27 | 36 | 0.60 | 56 | 0.93 |
| 17 | 0.28 | 37 | 0.62 | 57 | 0.95 |
| 18 | 0.30 | 38 | 0.63 | 58 | 0.97 |
| 19 | 0.32 | 39 | 0.65 | 59 | 0.98 |
| 20 | 0.33 | 40 | 0.67 | 60 | 1.00 |
To use the chart for a longer time, convert only the minutes and keep the whole hours as they are: 6 hours 52 minutes is 6 + 0.87 = 6.87 hours.
Why some decimals never end
An hour has 60 minutes, and 60 doesn’t divide evenly into tenths or hundredths for most minute values. One minute is 1/60 of an hour, which is 0.016666… with the 6 repeating forever. Only minute values that are multiples of 3 give a clean two-place decimal (3 minutes is 0.05, 6 minutes is 0.10), and only multiples of 6 give a clean tenth.
That’s why charts round. Two decimal places is accurate to within about 18 seconds of real time, which is close enough for most timesheets.
Rounding rules for timesheets
Many employers don’t record time to the minute. They round each punch, or each day, to a set increment. These are the three common ones:
| Increment | Each step | How minutes round (to the nearest step) |
|---|---|---|
| Nearest 5 minutes | about 0.08 hours | 1–2 round down, 3–4 round up to the next 5 |
| Nearest tenth of an hour | 6 minutes, 0.1 hours | 0–2 → .0, 3–8 → .1, 9–14 → .2, 15–20 → .3, 21–26 → .4, 27–32 → .5, 33–38 → .6, 39–44 → .7, 45–50 → .8, 51–56 → .9, 57–59 → next hour |
| Nearest quarter hour | 15 minutes, 0.25 hours | 0–7 → :00, 8–22 → :15, 23–37 → :30, 38–52 → :45, 53–59 → next hour |
The quarter-hour version is sometimes called the 7-minute rule, because 7 minutes past rounds down and 8 minutes past rounds up. The tenth-hour bands above round a value exactly halfway (3 minutes is 0.05) up to the next tenth.
In the US, the federal regulation on time records, 29 CFR 785.48, accepts rounding to the nearest 5 minutes, tenth or quarter hour only when, over time, it doesn’t result in employees being paid for less time than they actually worked. Some states set their own rules, so check your local labor rules before choosing a method. Rounding to the nearest step is different from always rounding down, which only ever moves time one way.
Avoid rounding twice
Rounded decimals drift when you add a lot of them. Three 20-minute tasks are exactly one hour, but 0.33 + 0.33 + 0.33 is 0.99. Across a month of short tasks, that gap grows.
- Add first, convert once. Total the hours and minutes for the day or week, then convert that total to a decimal.
- Keep more places while you work. Use four decimal places (0.3333) in the middle of a calculation and round only the final number.
- Check one way against the other. If the decimal total doesn’t convert back to the minutes you started with, a value has been rounded along the way.
The time calculator adds any number of durations in whole seconds and shows the result in hours and minutes and as decimal hours, so nothing drifts. Our guide to calculating hours worked applies the same idea to a full weekly timesheet.
In a spreadsheet
- Minutes in a cell (A2) to decimal hours:
=A2/60 - A time value such as 7:36 (A2) to decimal hours:
=A2*24, formatted as a number. Spreadsheets store times as fractions of a day, so 7:36 is stored as 0.3167 and multiplying by 24 gives 7.6. - Decimal hours (A2) back to a time:
=A2/24, formatted as[h]:mmso totals over 24 hours don’t wrap. - Nearest quarter hour:
=ROUND(A2*4,0)/4for decimal hours in A2. Use 10 instead of 4 for tenths.
For a span between two clock times, including ones that cross midnight, the time duration calculator gives total hours to two decimal places.
Frequently asked questions
How do you convert minutes to decimal hours?
Divide the minutes by 60. 45 minutes ÷ 60 = 0.75 hours, and 10 minutes ÷ 60 = 0.17 hours when rounded to two decimal places.
What is 7 hours and 30 minutes in decimal?
7.5 hours. 30 minutes is half an hour, so it becomes 0.5.
How many minutes is 0.1 hours?
Six minutes. Multiply the decimal by 60: 0.1 × 60 = 6.
What is 40 minutes as a decimal of an hour?
0.67 hours, rounded to two decimal places. The exact value is two-thirds of an hour, 0.6666…
Is 8.5 hours 8 hours 50 minutes?
No. 8.5 hours is 8 hours 30 minutes, because 0.5 × 60 = 30. 8 hours 50 minutes is about 8.83 hours.