Time to Decimal Converter
Turns hours and minutes into decimal hours for payroll, and back again.
Last updated
Your details
As HH:MM or HH:MM:SS.
Optional — gives the pay for this time.
Result
- Decimal hours
- 7.7500
- Hours and minutes
- 7:45
- Total minutes
- 465.00
- Total seconds
- 27,900
What a payroll system expects
7:45 on the clock…
decimal hours = hours + minutes ÷ 60
45 ÷ 60 = 0.7500
7 + 0.7500
7.7500
Formula — written step by step
7 hours 45 minutes on a timesheet…
decimal hours = hours + minutes ÷ 60
45 ÷ 60 = 0.75
7 + 0.75
7.75 decimal hours
The trap is treating 7:45 as 7.45. Minutes run to sixty, not a hundred, so 45 minutes is three quarters of an hour — 0.75, not 0.45. That gap of 0.30 hours is eighteen minutes of unpaid work per shift.
A worked example
What the 7.45 mistake costs
- Shift
- 7 hours 45 minutes
- Entered as
- 7.45 instead of 7.75
- Rate
- 20 per hour
- Correct: 7.75 × 20 = 155.00
- Wrong: 7.45 × 20 = 149.00
- Short by 6.00 per shift
- Over 250 shifts a year
1,500 a year underpaid
The error is invisible in a spreadsheet because 7.45 is a perfectly plausible number. It only shows up when someone checks the arithmetic against the clock. Converting properly at entry is the fix; converting at the end is too late.
How to use this calculator
- Enter the time as it appears on the clock — 7:45, or 7:45:30 if seconds matter.
- Read the decimal figure. This is what payroll and billing systems expect.
- Switch the mode to go the other way, turning a decimal figure back into hours and minutes.
- Add an hourly rate to see the pay, which is the quickest way to spot a conversion error.
Why payroll wants decimals
Clock time is base sixty: sixty minutes make an hour. Money is base ten. Multiplying 7:45 by an hourly rate requires the time in the same base as the money, which is why every payroll and billing system asks for decimal hours.
The conversion is simply minutes divided by sixty, added to the hours. Forty-five minutes is 0.75 of an hour, not 0.45 — and that difference of 0.30 hours is eighteen minutes, which compounds quickly across a workforce.
Rounding conventions
Many employers round to the nearest quarter hour, which keeps timesheets tidy and produces clean decimals of .25, .5 and .75. In the United States this is permitted under the Fair Labor Standards Act provided the rounding is neutral — it must cut both ways over time, not systematically favour the employer.
Rounding that always goes down is wage theft, however small each instance. Six minutes a day is half an hour a week and roughly three days of unpaid work a year.
Seconds, and where they matter
For most timesheets, seconds are noise. For billing by the minute — legal work, support calls, machine time — they are not, and this converter handles HH:MM:SS as readily as HH:MM.
One second is 0.000278 hours, which looks negligible until it is multiplied by thousands of billable events. Where that matters, convert from a total in seconds rather than from a rounded clock reading, and round only once at the end.
Formula & methodology
What this calculator assumes
- Clock time is base sixty and money is base ten, which is why payroll systems require decimal hours. 7:45 is 7.75, not 7.45.
- Rounding to the nearest quarter hour is common and lawful in the United States provided it is neutral over time; rounding that consistently favours the employer is not.
- Two decimal places is enough for payroll. Billing by the minute should keep four.
Sources
- US Department of Labor, 29 CFR 785.48 — rounding practices for recording working time, 2011.
Minutes as decimal hours
| Minutes | Decimal | Minutes | Decimal |
|---|---|---|---|
| 5 | 0.083 | 35 | 0.583 |
| 10 | 0.167 | 40 | 0.667 |
| 15 | 0.25 | 45 | 0.75 |
| 20 | 0.333 | 50 | 0.833 |
| 25 | 0.417 | 55 | 0.917 |
| 30 | 0.5 | 60 | 1.0 |
Only the quarter hours — 15, 30 and 45 — convert to tidy decimals. Everything else recurs, which is why rounded timesheets tend to use quarter-hour increments.
Frequently asked questions
Is 7:30 the same as 7.30?
No. 7:30 is seven and a half hours, which is 7.5 in decimal. Writing 7.30 understates it by twelve minutes.
How do I convert minutes to decimal?
Divide by 60. Twenty minutes is 20 ÷ 60 = 0.333 hours.
Why do most minutes give a recurring decimal?
Because 60 does not divide evenly into powers of ten. Only minutes that are factors of 60 — 6, 12, 15, 30 — give terminating decimals.
Should I round the decimal?
Two places is enough for payroll and matches quarter-hour rounding. For billing by the minute, keep four.