Hours and Minutes to Decimal

The formula, with the minutes in the numerator

Decimal hours = hours + minutes / 60. The minutes are the only part that changes shape. Thirty minutes divided by sixty is one half, so any hour-and-a-half clock time ends in .50. Fifteen minutes is .25. Forty-five minutes is .75. Six minutes is .10, one tenth of an hour. The hours stay whole. Eight hours do not become a fraction. They stay 8, and the fraction is added beside them.

The mistake this page is for is writing the minutes after the dot. 8:30 is eight hours and thirty minutes. 8.30 is eight hours and eighteen minutes, because 0.30 × 60 = 18. Payroll software multiplies the decimal, so 8.30 times an hourly rate pays for eighteen minutes, not thirty. If the number in front of you still has a colon, or the words “hours” and “minutes,” convert it before it goes on a timesheet. Paste 8:30, 8h 30m, or “8 hours 30 minutes” into the paste box. Each of those is 8.50.

A few lines, then one total

A day is rarely one number. 7:30 plus 8:15 plus 45 minutes is 7.50 + 8.25 + 0.75. The exact sum is 16.50. Add the unrounded values, then choose the decimal places for the display. Rounding each line to two places and then adding those rounded lines can drift by a few minutes over a week. The batch box under the form does the addition in that order. Two decimal places is the default because that is the usual payroll display. You can show four places when you want to see that one minute is 0.0167, which will display as 0.02 if you round too early.

The reverse direction, decimal hours back to a clock, is decimal hours to hours and minutes. The lookup tables, quarter hours through 12:00 and minutes 0 through 59, are the hours to decimal chart. The home hours to decimal calculator keeps both directions, the batch, and the minute chart on one page. Once the week is a decimal, price it on the overtime calculator. Hours past 40 in the workweek use the 1.5× line. A block that is already overtime can go straight to the time and a half calculator.

What the converter will not accept

Minutes in the minutes field have to be a whole number from 0 to 59. 8:60 is not a time. Put that hour in the hours field instead. Negative time is rejected. The math stays in the browser. Nothing on the form is uploaded, and the result is an estimate for a timesheet, not a legal ruling about which hours counted as work. How payroll rounds tenths and hundredths is discussed on hours to decimal payroll.