Time Converter: Hours & Minutes to Decimal Hours

7.5 hours is 7 hours 30 minutes, not 7:50

The most common time-conversion mistake is reading the digits after the decimal point as minutes. They are fractions of an hour: 0.5 is half an hour, 30 minutes. So 7.5 hours is 7:30, and 7:50 is 7.8333 hours.

It matters most when time is multiplied by a rate. At $20 an hour, 7 hours 30 minutes is 7.5 × $20 = $150. Typing it into a spreadsheet as 7.30 instead gives $146 — $4 short on one day.

Common shift lengths in hours and minutes

The five-day column multiplies the decimal hours by 5 and converts the total once, so nothing is lost to rounding along the way.

8.33 appears twice. Taken exactly, 8.33 hours is 8 h 19 min 48 s. But 8.33 is usually 8⅓ hours (8 h 20 min) rounded to two decimals, so both are shown. Decimals marked … repeat and are rounded to four places.

Common decimal hours in hours and minutes, and five days of each

Adding a 30-minute unpaid break

“8 hours with a 30-minute unpaid break” can mean two different things, so the table shows both:

• Paid hours plus the break: you are paid for 8 hours and also take an unpaid 30-minute break, so you are at work for 8 h 30 min from start to finish.
• Time at work including the break: you are at work for 8 hours, 30 minutes of it unpaid, so the paid time is 7 h 30 min (7.5 hours).

The table does the arithmetic only. Whether a break is paid, how long it is, and how time is recorded are set by the employer and local rules.

With a 30-minute unpaid break, read both ways

Minutes to decimal hours

Each minute is 1/60 of an hour, about 0.0167. The quarter hours come out exactly — 15 minutes is 0.25, 30 is 0.5, 45 is 0.75 — and so does every multiple of 3 minutes: 3 minutes is 0.05 of an hour, 6 minutes is 0.1. Most other minutes give a repeating decimal: 20 minutes is 0.3333…, shown here to four places.

Adding up a week: convert the total, not each day

When each day is rounded to two decimal places before adding, the small errors add up. Five days of 7 hours 20 minutes:

• Rounding each day: 7:20 is 7.3333, rounded to 7.33; 5 × 7.33 = 36.65 hours.
• Converting the total: 5 × 7 h 20 min = 36 h 40 min = 36.6667 hours, or 36.67 to two places.

The second is the accurate figure. Adding the hours and minutes first, then converting once, avoids the drift.

Rounding to 6 or 15 minutes

Some timekeeping systems record time in tenths of an hour (6 minutes) or quarter hours (15 minutes). The rounding setting on the converter shows what a time becomes on those marks. It rounds to the nearest mark, and a time exactly halfway goes up: 3 minutes becomes 6, and 7 minutes stays at the hour on a 15-minute scale while 8 goes up to 15.

This is a conversion option, not a rule. Whether time is rounded at all, and how, is up to the employer. Employer timekeeping and rounding policies vary, and applicable laws may restrict certain rounding practices. Use the setting to check a figure against your own system, not to decide what you should be paid.

Nearest 6 minutes (tenths of an hour): halfway rounds up

Nearest 15 minutes (quarter hours): halfway rounds up

What this converter does and does not handle

• Minutes over 59 carry. 0 hours 90 minutes is 1.5 hours.
• Seconds are shown when the decimal does not land on a whole minute. 8.33 hours is 8 h 19 min 48 s, because 8.33 is itself a rounded figure; the exact decimal for 8 h 20 min is 8.3333…
• The chart values are rounded too. 1 minute is 0.016666… hours, shown as 0.0167; typing 0.0167 back in gives 1 min 0.1 s.
• Up to 1,000,000 hours. Anything larger is refused rather than shown with lost digits.
• Negative times are not accepted. These are durations, so they start at zero.
• It converts a length of time, not clock times. To find the hours between a start and finish time, subtract first; a shift that runs past midnight needs 24 hours added to the finish.