How to calculate hours between two times
The quickest reliable method is to turn both times into minutes after midnight, subtract, and turn the answer back into hours.
- Convert to 24-hour time. 9:00 AM stays 9:00; 5:30 PM becomes 17:30.
- Subtract. 17:30 − 9:00 = 8 hours 30 minutes.
- Remove unpaid breaks. 8:30 − 0:30 = 8 hours.
When the minutes of the end time are smaller than the start time’s, borrow an hour. For 8:45 AM to 3:20 PM: 15:20 − 8:45 → borrow one hour so 15:20 becomes 14:80, then 14:80 − 8:45 = 6 hours 35 minutes.
Overnight shifts
If a shift ends the next day, add 24 hours to the end time. 10:00 PM to 6:00 AM is 22:00 to 30:00, which is 8 hours. The calculator detects this automatically whenever the end time is earlier than the start time.
Hours and minutes vs. decimal hours
6 hours 35 minutes is not 6.35 hours. Divide the minutes by 60: 35 ÷ 60 = 0.58, so the decimal figure is 6.58 hours. Payroll uses decimals because they can be multiplied by an hourly rate directly: 6.58 × $18 = $118.44.
| Minutes | Decimal | Minutes | Decimal |
|---|---|---|---|
| 5 | 0.08 | 35 | 0.58 |
| 10 | 0.17 | 40 | 0.67 |
| 15 | 0.25 | 45 | 0.75 |
| 20 | 0.33 | 50 | 0.83 |
| 25 | 0.42 | 55 | 0.92 |
| 30 | 0.50 | 60 | 1.00 |
See every minute from 1 to 60 on the minutes to decimal chart.
Common uses
- Checking a single shift before you submit a timesheet.
- Working out billable hours for a client.
- Finding how long you volunteered, studied or drove.
For a full week of shifts, use the time card calculator. To measure across several days, use the time duration calculator.
Working out pay? See how overtime pay is calculated for hours over 40, and the time clock rounding rules if your employer rounds your punches.
Sources and limits
The rules on this page come from these official sources, which we read on September 26, 2026. Pay rules change and differ by state, and some employers and union contracts pay more than the law requires. This page is general information, not legal or payroll advice. If you think you have been underpaid, contact the U.S. Department of Labor's Wage and Hour Division or your state labor department.