How to convert minutes to decimal hours

By Dexaloop · Updated 27 October 2026 · Checked against the sources listed below

To convert minutes to decimal hours, divide the minutes by 60. So 15 minutes is 0.25 hours, 30 minutes is 0.5, and 45 minutes is 0.75. For a time like 7 hours 40 minutes, divide only the minutes and add the result to the whole hours: 40 ÷ 60 = 0.667, so the total is 7.67 hours. Payroll needs this form because a pay rate is per hour, and you can only multiply a rate by a single number, not by hours and minutes. The US rounding rules quoted below were checked on 27 October 2026; this is general information, and state law or your contract can add more.

Why decimal hours exist

Clock time counts in sixties. Money counts in tens. A time card might say 7:40, but 7:40 is not seven point four of anything. To multiply it by $20 an hour, you need it as hours and a fraction of an hour, written in decimals. That is all decimal hours are: the same amount of time written in a form a calculator can multiply.

The formula is short:

decimal hours = whole hours + (minutes ÷ 60)

Minutes to decimal hours table

Notice the pattern. Any number of minutes that divides evenly into a "nice" fraction with 2, 4, 5 or 10 at the bottom comes out exact. Anything that needs a 3 at the bottom, such as 20 minutes (1/3) or 10 minutes (1/6), repeats forever. A repeating decimal must be rounded somewhere, and that is where small pay differences creep in.

Converting decimal hours back to minutes

Reverse the sum: multiply the decimal part by 60.

• 8.25 hours: 0.25 × 60 = 15, so 8 hours 15 minutes.
• 6.4 hours: 0.4 × 60 = 24, so 6 hours 24 minutes.
• 3.9 hours: 0.9 × 60 = 54, so 3 hours 54 minutes.

This is the check to run whenever a payslip shows decimal hours that look odd. If your card said 7 hours 30 minutes and the payslip says 7.30, multiply back: 0.30 × 60 is 18 minutes. You have been paid for 12 minutes less than you worked. The right figure is 7.5.

Worked example: convert the total, not each day

Alex works 7 hours 20 minutes every day for five days and is paid $18 an hour.

Method A, round each day: 20 ÷ 60 = 0.333..., rounded to 0.33, so each day is 7.33 hours. Five days is 36.65 hours. Pay: 36.65 × $18 = $659.70.

Method B, add first, convert once: five days of 7:20 is 35 hours and 100 minutes, which is 36 hours 40 minutes. 40 ÷ 60 = 0.6666..., so the week is 36 2/3 hours. Pay: 36 2/3 × $18 = $660.00.

The difference is 30 cents for one person in one week, caused only by rounding a repeating decimal five times instead of once. Across many staff and many weeks, it adds up. The safer habit is to total hours and minutes first, convert once, and keep at least two decimal places, or better, multiply using the exact fraction.

Rounding clock times versus rounding decimals

These are two different things that often get mixed together.

• Rounding decimals is a maths step: writing 0.3333... as 0.33. On its own it moves pay by a few cents per entry, as Alex's 30 cents a week shows, which adds up across a payroll.
• Rounding clock times is a pay policy: recording a punch at 8:07 as 8:00, or 8:08 as 8:15. That can move whole minutes.

In the US, the federal rule on clock rounding is in 29 CFR 785.48(b). It describes the practice of recording start and stop times "to the nearest 5 minutes, or to the nearest one-tenth or quarter of an hour." It then sets the condition. The practice is accepted "provided that it is used in such a manner that it will not result, over a period of time, in failure to compensate the employees properly for all the time they have actually worked."

In plain terms, rounding has to be to the nearest mark, both up and down, and has to even out. A rule that only ever rounds down fails that test.

A tenth of an hour has an exact midpoint at 3 minutes, so it is left out of the table: how a punch at exactly 3 minutes past is treated is a matter for the employer's written policy, applied the same way both ways.

Doing it in a spreadsheet

Spreadsheets store a time as a fraction of a day. Microsoft describes the time values in Excel as ranging "from 0 (zero) to 0.99988426," which covers midnight up to one second before the next midnight. To turn a time cell into decimal hours, multiply by 24. A cell showing 7:40 holds 0.3194... of a day; times 24 gives 7.6666... hours. Format the result as a number, not a time, or it will still display as a clock time.

Common mistakes

• Writing the minutes after the point. 8 hours 45 minutes is 8.75, not 8.45.
• Rounding every line. Round once at the end of the week, not on each day.
• Dropping to one decimal place. 7.67 rounded to 7.7 overpays, and 7.33 rounded to 7.3 underpays. Keep two places at least.
• Confusing clock rounding with decimal rounding. One is a policy with legal limits, the other is arithmetic.
• Carrying minutes past 60. 7 hours 75 minutes is 8 hours 15 minutes, or 8.25.

For a quick conversion, either direction, the converter below does the division and shows the result to two places.

Questions

Sources

• 29 CFR 785.48, Use of time clocks (Legal Information Institute, Cornell Law School)
• Microsoft Support: TIME function

This guide is general information, not legal, tax or financial advice. Rules change; check the official source for your own case. Found a mistake? Email support@dexaloop.com.

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