TIMESHEET GUIDE
How to calculate decimal hours for a timesheet
A timesheet may ask for decimal hours even when you record your day as clock times. Calculate the duration, subtract any unpaid break, then convert the remaining minutes into a fraction of an hour.
Start with the paid duration
Clock time and duration answer different questions. The time from 09:00 to 17:30 is 8 hours 30 minutes. If that period includes a 30-minute unpaid break, the paid duration is 8 hours. The value to enter is therefore 8.00 decimal hours.
| Start–end | Unpaid break | Paid duration | Decimal hours |
|---|---|---|---|
| 09:00–17:30 | 30 min | 8 h 00 min | 8.00 |
| 08:15–16:30 | 45 min | 7 h 30 min | 7.50 |
| 07:40–16:10 | 30 min | 8 h 00 min | 8.00 |
The conversion is whole hours + remaining minutes ÷ 60. For example, 7 hours 30 minutes becomes 7 + 30 ÷ 60 = 7.50 hours. Enter 7 hours and 30 minutes in the calculator if you want to check an individual duration.
A shift without tidy quarter-hours
Real records do not always end at :00, :15 or :30. Take a day from 08:17 to 16:52: the elapsed time is 8 hours 35 minutes. Subtract a 30-minute unpaid break and you have 8 hours 5 minutes of paid time. Five minutes is 5 ÷ 60 = 0.0833… hour, so the displayed total is 8.08 decimal hours.
It helps to keep the two notations separate: 8:05 means eight hours and five minutes; 8.08 means a number of hours rounded to two decimal places. Converting the rounded number back gives 8 hours and 4.8 minutes. That small difference is why the original minutes should stay in your records.
What if a shift crosses midnight?
Consider a shift that begins at 22:15 and ends at 06:45 the next day. From 22:15 to midnight is 1 hour 45 minutes; from midnight to 06:45 is 6 hours 45 minutes. Together that is 8 hours 30 minutes. With a 45-minute unpaid break, the paid duration is 7 hours 45 minutes = 7.75 decimal hours.
Record the start and end dates as well as the times. Without dates, a spreadsheet may treat 06:45 as earlier than 22:15 and produce a negative duration. The Excel guide explains how Excel stores time and converts a duration into decimal hours.
Convert minutes without mixing up hundredths
Decimal hours split an hour into hundredths; a clock hour has 60 minutes. As a result, 0.10 hour is 6 minutes, and 0.25 hour is 15 minutes. Ten ordinary minutes are 10 ÷ 60 = 0.1666… hour, often displayed as 0.17. Reading “7.30 hours” as “7 hours 30 minutes” overstates the time: 0.30 × 60 is 18 minutes.
Use the 1–60 minute chart for quick lookups or its downloadable PDF and spreadsheet when working offline.
When should you round?
Keep the actual minutes while adding several periods. Three 20-minute jobs add up to 60 minutes, which is exactly 1.00 hour. If each job is rounded to 0.33 first, their sum is only 0.99. Round the total after adding the unrounded durations unless the timesheet or payroll rules explicitly require a different method.
| Method | Calculation | Result |
|---|---|---|
| Add minutes first | (20 + 20 + 20) ÷ 60 | 1.00 h |
| Round each entry first | 0.33 + 0.33 + 0.33 | 0.99 h |
Formatting a spreadsheet result to show two decimal places changes its appearance, while rounding a formula changes the number used in later calculations. For totals, keep the precise durations in the source cells. Follow your employer’s actual time-recording and rounding requirements for an official timesheet.
A quick check before submitting
- Use the correct dates for shifts that run past midnight.
- Subtract only breaks that are unpaid and actually belong to the period.
- Sum durations in minutes or precise spreadsheet time values before rounding.
- Check whether the form asks for hours:minutes or decimal hours; 7:30 and 7.50 describe the same duration in different formats.