Time to Decimal Calculator
Convert hours and minutes to decimal hours for timesheets, payroll, or billing. Formula: hours + (minutes ÷ 60).
Reviewed & updated for 2026 by Rakesh Choudhary, PhDMethodology & sources · How we calculate
Common time-to-decimal conversions
| Time (h:mm) | Decimal hours |
|---|---|
| 0:15 | 0.25 |
| 0:30 | 0.5 |
| 0:45 | 0.75 |
| 1:00 | 1.0 |
| 7:30 | 7.5 |
| 8:00 | 8.0 |
| 8:15 | 8.25 |
| 8:30 | 8.5 |
| 8:45 | 8.75 |
| 9:00 | 9.0 |
| 12:30 | 12.5 |
| 40:00 | 40.0 |
Why payroll, billing, and HR all use decimal hours
Multiplying time by money is awkward in base-60. "What's 8 hours 47 minutes times $32.50/hour?" means turning 47 minutes into a fraction of an hour first. In decimals it is one multiplication: 8.7833 hours × $32.50 = $285.46. That is why timesheets and invoices that multiply by a rate work in decimal hours.
This calculator does no rounding. If your employer rounds clock punches to set increments, ask how, and check the result against your own record of hours.
A short cheat sheet: 6 minutes = 0.1, 15 minutes = 0.25, 20 minutes = 0.333, 30 minutes = 0.5, 36 minutes = 0.6, 45 minutes = 0.75 hours. Knowing these few makes checking a timesheet much quicker.
Where decimal time conversions trip people up
- Dividing minutes by 100 instead of 60: The most common mistake. 8:30 is NOT 8.30, it's 8.5. Spreadsheets storing "8.30" as text and then doing math get systematically wrong answers.
- Crossing midnight without adjusting: Work 10 PM to 6 AM and plain subtraction gives -16 hours. Add 24 to handle the wrap.
- Lunch breaks counted as work: A 9-to-5 with a 1-hour unpaid lunch is 7 hours, not 8. Always subtract unpaid breaks.
- Spreadsheet time format confusion: A spreadsheet cell that holds a time as a fraction of a day shows 8 hours as 0.333. To get decimal hours, multiply the cell by 24.
- Mixing 12-hour and 24-hour input: Did "1:00" mean 1 AM or 1 PM? Use 24-hour or am/pm tags to remove ambiguity in tracking systems.
Worked examples for invoicing and overtime
Freelance invoice: You logged 12 sessions totaling 27 hours 45 minutes at $85/hour. Convert: 27 + 45/60 = 27.75 hours. Total: 27.75 × $85 = $2,358.75. Invoice in decimal hours so the client doesn't have to convert "27:45" themselves.
Overtime calculation: You worked 47:20 in a week at $18/hour. Convert: 47 + 20/60 = 47.333 hours. Regular: 40 × $18 = $720.00. Overtime: 7.333 × $27 (1.5×) = $198.00. Total: $918.00. Federal law requires at least time and a half for a covered, non-exempt employee's hours over 40 in a workweek (U.S. Department of Labor).
Time spent in meetings tracking: If your week breaks down as 12:15 in meetings + 18:30 on focused work + 6:45 in code reviews + 2:30 on admin, hand-adding gives 38 hours 120 minutes, which carries to 40 hours flat. Converting each to decimal (12.25, 18.5, 6.75, 2.5) and summing gives 40.0 directly, without the carry.
FAQs
How do you convert time to decimal?
Divide the minutes by 60 and add the hours. 8:30 becomes 8 + 30/60 = 8.5; 7:45 is 7.75; 8:15 is 8.25. The divisor is 60, never 100.
What is 8:30 in decimal?
8.5 hours. Thirty minutes is half of an hour.
What is 6:45 in decimal?
6.75 hours, since 45 ÷ 60 = 0.75. That is the figure a billable-hours timesheet wants.
How do you convert decimal back to time?
Keep the whole number as hours and multiply what's after the point by 60 for minutes. 7.4 hours is 7 hours plus 0.4 × 60 = 7 hours 24 minutes; 8.75 is 8 hours 45 minutes.
Why use decimal time?
Because pay and billing are hours times a rate, and that is easy only in decimals: 8.5 hours × $25 = $212.50, where 8 h 30 min × $25 needs converting first. Adding is simpler too: 1.25 + 2.75 = 4.0, the same as 1:15 + 2:45 = 4:00.