Converter

Time to Decimal Calculator

Turn clock times into decimal hours: a start and end time with an unpaid break, or a single reading such as 8:30.

  • InputClock in / out
  • BreakDeducted
  • OvernightHandled

Start and end time to decimal hours

Decimal hours worked

8.25

8 h 15 min worked after a 30-minute break = 8.2500 hours

Single clock time to decimal

Decimal hours

8.50

8 + 30 ÷ 60 = 8.5000 hours

00:0006:0012:0018:0000:008:3017:158:15 worked after a 30-minute break = 8.25 hours

How a clock-in and clock-out become decimal hours

Clock inClock outWorked8:30 am = 510 min since midnight5:15 pm = 1035 min525 − 30 break = 495 min ÷ 60 = 8.25 h

Each bar is minutes since midnight. The worked bar is the difference with the unpaid break cut out of it.

Count the minutes between the two punches, take off any unpaid break, and divide by 60. The easiest way to count is to turn each clock time into minutes since midnight: 8:30 am is 8 × 60 + 30 = 510 and 5:15 pm is 17 × 60 + 15 = 1,035. The difference is 525 minutes; less a 30-minute break leaves 495 minutes, and 495 ÷ 60 = 8.25 hours.

When a shift crosses midnight the end time is smaller than the start time, so add 24 hours (1,440 minutes) before subtracting. A 10:00 pm to 6:30 am shift is (390 + 1,440) − 1,320 = 510 minutes, which is 8.5 hours before any break.

Converting a single clock reading

A time such as 8:30 already has its hours in front. Only the minutes change: 30 ÷ 60 = 0.5, so 8:30 is 8.5 in decimal. The colon is the giveaway that a value is clock time; 8.30 with a point would mean 8 hours and 18 minutes. If your hours and minutes are already separate numbers rather than a clock reading, the hours to decimal calculator takes them as two fields.

30min + 8 h

Only the minutes move the dial; the hours ride along in front.

Clock timeDecimal hours
7:307.50
7:457.75
8:108.17
8:208.33
8:408.67
9:059.08
9:509.83
10:1510.25