Time to decimal calculator
Enter hours and minutes, get decimal hours.
How do I convert hours and minutes to decimal hours?
Divide the minutes by 60 and add them to the hours: 7 hours 45 minutes is 7 + 45 ÷ 60 = 7.75 hours.
How do I convert decimal hours back to minutes?
Multiply the decimal part by 60: 7.75 hours is 7 hours and 0.75 × 60 = 45 minutes.
Why do timesheets use decimal hours?
Pay is hours × rate, and that needs a decimal: 7:45 at $20 an hour is 7.75 × $20 = $155, not 7.45 × $20 = $149. Writing 7:45 as 7.45 is the most common mistake, because 0.45 of an hour is 27 minutes, not 45.
What are common minute conversions?
15 minutes = 0.25 h, 30 minutes = 0.5 h, 45 minutes = 0.75 h, and 20 minutes ≈ 0.3333 h. The table lists every 5 minutes. One tenth of an hour is exactly 6 minutes, so 0.1, 0.2, 0.3 … run in steps of 6 minutes.
Can I enter seconds?
Yes — write 1:30:30 or 1h 30m 30s; that is 1.5083 hours.
Worked example: a timesheet with rounding
An employee clocks 7 hours 52 minutes. In decimal hours that is 7 + 52 ÷ 60 = 7.8667. U.S. Department of Labor rules (29 CFR 785.48) allow an employer’s time clock to round start and stop times to the nearest 5 minutes, the nearest tenth of an hour or the nearest quarter hour, provided that the rounding averages out over time so employees are paid for all the time they work. Rounded to the nearest tenth the day becomes 7.9 hours, and to the nearest quarter hour it becomes 7.75. At $20 an hour the exact pay is $157.33, against $158.00 and $155.00 after rounding.
How many decimals should I keep?
Keep at least four. A third of an hour is 0.3333…; entering 0.33 for 20 minutes loses 0.0033 hours, about 12 seconds, each time. Across 20 shifts that is 4.0 minutes of unpaid time. Convert only once at the end, from the full-precision total, rather than rounding every line.
Common mistakes when converting time
First, reading 7.45 as 7 hours 45 minutes. Decimal hours are not the clock face, and 7.45 is 7 hours 27 minutes. Second, rounding each entry before adding; round the total instead. Third, adding clock times as if they were decimals: 1:40 + 2:30 is 4:10, not 3.70. Convert both to decimals or add hours and minutes separately, then carry every 60 minutes. Fourth, forgetting the break: subtract unpaid breaks before converting, since a 30-minute lunch is 0.5 hours. Fifth, mixing a time of day with a duration; 8:15 PM is a clock time, while 8 hours 15 minutes is an amount of time.
Worked example: adding a week of shifts
Five days are clocked as 7:52, 8:07, 7:38, 8:21, 6:44. In decimal hours these are 7.8667, 8.1167, 7.6333, 8.3500, 6.7333, which add up to 38.7000 hours. Converting back, that is 38 hours and 42 minutes, and the same total comes from adding the clock times directly. At $20 an hour the exact pay is $774.00. If instead each day were rounded to the nearest quarter hour before adding, the total would be 38.50 hours, a difference of 0.20 hours; under 29 CFR 785.48 such rounding is acceptable only if it averages out over time so employees are paid for all the time they work, so check the rules that apply to your workplace before you adopt it.
Minutes that do not divide evenly
Many minute counts turn into repeating decimals, which is why the number of decimals you keep matters:
- 1 minute = 0.0167 hours
- 2 minutes = 0.0333 hours
- 5 minutes = 0.0833 hours
- 10 minutes = 0.1667 hours
- 12 minutes = 0.2000 hours
- 20 minutes = 0.3333 hours
- 25 minutes = 0.4167 hours
- 40 minutes = 0.6667 hours
- 50 minutes = 0.8333 hours
- 55 minutes = 0.9167 hours
To convert in the other direction, multiply the decimal part by 60 and round to the nearest minute at the end: 0.4167 hours × 60 is about 25.0 minutes. A decimal that comes from a rounded value, such as 0.42, converts back to 25.2 minutes, which shows how much a two-digit decimal loses. For durations that include seconds, divide by 3,600 instead: 1,800 seconds = 0.5 hours.
Sources: 29 CFR § 785.48 (U.S. Department of Labor, Wage and Hour Division: use of time clocks and rounding practices). The conversions follow from the definition of the hour as 60 minutes. Related: hours calculator, time card calculator, time calculator, overtime calculator and salary calculator.