Hours and Minutes Calculator

How to add and subtract hours and minutes by hand

Add the hours and the minutes separately, then carry every 60 minutes over as one hour. The calculator's starting rows work as an example: 7 h 45 min + 8 h 30 min + 9 h 50 min.

Subtracting works the other way round: take away the minutes first, and when there aren't enough, borrow 60 minutes from the hours. For 8:15 − 2:40, 15 minutes can't cover 40, so 8:15 becomes 7:75, and 7:75 − 2:40 = 5:35. In the calculator, set that row to − and it does the borrowing for you. If the subtracted rows outweigh the added ones, the total gets a minus sign, like -1:15.

A total past 24 hours is still just hours. 26:05 means 26 hours and 5 minutes of time, not 2:05 the next day, so the calculator never rolls a total over to a time of day. It shows the same total in words, in decimal hours (26.08) and in minutes (1,565). Working from clock times instead? The shift length calculator turns a start and end time into hours, and the military time converter reads 24-hour times.

Hours and minutes vs. decimal hours

Minutes carry at 60 and decimals carry at 10. That's why "7.30" on a phone calculator isn't 7 hours 30 minutes. Thirty minutes is half an hour, so 7 h 30 min is 7.50 decimal hours, while 7.30 hours is 7 hours 18 minutes. To convert, divide the minutes by 60 and add the hours: 1 h 3 min is 1 + 3 ÷ 60 = 1.05 hours, or 63 minutes.

Payroll usually works in decimal hours because a rate multiplies cleanly. This calculator shows the decimal total rounded to 2 places, but its pay line uses the exact minutes: rate × minutes ÷ 60. For 7 h 20 min at $18.00, that's 18 × 440 ÷ 60 = $132.00. Multiply the rounded 7.33 hours by $18.00 and you get $131.94, so a pay stub that multiplies rounded hours can be a few cents off this figure.

For one value at a time, the Payroll Time Converter turns hours and minutes into decimal hours and back, with a minute-by-minute chart. Minutes to Decimal Conversion for Payroll walks through the formula.

Why spreadsheets and calculators get timesheet totals wrong

Excel treats a time like 12:45 as a time of day, so a sum in its default h:mm format wraps at 24 hours. Microsoft's own example: 12:45 + 15:30 shows 4:15. Give the total cell the custom format [h]:mm;@ and it shows 28:15, the real 28 hours and 15 minutes (Microsoft Support). Put 12:45 and 15:30 in two rows here and you get 28:15 (28.25 hours) with nothing to format.

A phone calculator goes wrong a different way: it carries at 100. 7.45 + 8.30 gives 15.75, but 7 h 45 min + 8 h 30 min is 16:15, or 16.25 hours.

Rounding each day before you add them up throws the total off too. Five days of 7 h 20 min are 36:40, which is 36.67 hours. Round each day to 7.33 first and the week comes to 36.65 hours; at $18.00 an hour, that pays $659.70 instead of $660.00. Add in hours and minutes and round once, at the end. This calculator keeps every row in whole minutes and rounds only the decimal it displays, so the h:mm, decimal and minute totals can be pasted wherever you need them.

Checking a week of hours against your pay stub

Federal rules require employers to record the "Hours worked each workday and total hours worked each workweek" (29 CFR 516.2(a)(7)), but not how: "Employers may use any timekeeping method they choose" (DOL Fact Sheet #21). Adding up your own hours is the quickest way to check their total.

To check overtime, total one workweek at a time. A workweek is "a fixed and regularly recurring period of 168 hours" (DOL Fact Sheet #23), and overtime is counted week by week, so enter only that week's hours. If the total passes 40:00, the overtime calculator splits regular and overtime pay, and the work schedule hours counter shows how many hours you have left before overtime.

Your timecard can also differ from your own log because of rounding. Federal rules let employers round punches to the nearest 5 minutes, tenth of an hour or quarter hour, as long as the rounding doesn't, over a period of time, fail to pay employees for all the time they actually worked (29 CFR 785.48(b)). The "7-minute rule" many employers use for quarter-hour rounding is common practice, not wording from the regulation. The time clock rounding calculator shows how your punches round, and Timesheet Rounding: The 7-Minute Rule explains it.

The best check is a record you keep yourself. If your employer's total and yours don't match, a log you made at the time shows which days differ; Proving Hours Worked Without a Time Clock covers what to keep. TimeClock44 records each shift as you clock in and out with one tap, totals every day and week in hours and pay, and exports the week as a CSV or PDF timesheet to hold up against your pay stub. Our guide on how to track work hours covers the habit.