Guide · Hours
Minutes to Decimal Hours: Why 8.30 Is Not 8:30
Convert minutes to decimal hours by dividing by 60. A 0–60 minute chart, the rounding rule, and the payroll errors that come from mixing 8:30 and 8.30.
Updated · 4 min read
Time cards & hours · calculator
Time to decimal calculator
Hours and minutes to the decimal hours payroll multiplies by your rate — and back again, with the exact value when it never ends.
Convert
ExampleI have
Like 7:45, 7 45 or 7h 45m. A plain number is whole hours.
Try an example
In decimal hours
7.75hours
7:45 = 465 ÷ 60 = exactly 7.75 hours.
In tenths, as some time clocks print it: 7.8 hours.
8.30 hours is not 8:30
The digits after the point are hundredths of an hour, not minutes: 8.30 hours is 8:18, and 8:30 is 8.50 hours.
7:45 is 7.75 hours.
RuleDecimal hours = minutes ÷ 60, rounded half up to the hundredth, once; minutes = decimal hours × 60Sources checked How the math works ↓
Two rulers, one hour
60 minutes · 100 hundredthsPlus 7 whole hours: 7:45 = 7 h + 45 min = 7 h + .75 h.
Scale: both rulers are one hour long · 1 minute = 5.6 px · 0.01 h = 3.4 px
15 minutes is .25, 30 is .50 and 45 is .75 — the dotted lines. Every 6 minutes is one tenth (.10).
Calculated with Punch Clock Math · rules checked October 22, 2026 · an estimate, not legal or tax advice · punchclockmath.com
How the math works
An hour has 60 minutes but a decimal has 100 hundredths, so the same hour is cut two ways.
- Hours and minutes → decimal7:45 → 45 ÷ 60 = 0.75 → 7.75 hours.Whole hours stay whole; only the minutes are divided by 60.
- Round once, at the end7:40 → 40 ÷ 60 = 0.666… → 7.67 hours (half up to the hundredth).A total is added in minutes first and converted once — never the sum of rounded decimals.
- Decimal → hours and minutes8.30 hours → 0.30 × 60 = 18 minutes → 8:18.The digits after the point are hundredths, not minutes: 8.30 is not 8:30. When the minutes are not whole (0.33 × 60 = 19.8), they are rounded to the nearest minute and marked “not exact”.
- Tenths of an hour1 tenth = 6 minutes: 7:48 = 7.8 hours.Some time clocks record tenths. Rounding punch times to the nearest 5 minutes, tenth of an hour (6 min) or quarter hour (15 min) is accepted for enforcement, provided that over time it does not underpay employees for time actually worked.29 CFR 785.48
What this doesn’t cover
- Seconds: time cards record minutes, so seconds are not modeled.
- Rounding of punches: this converts a time exactly; it does not move punches to the nearest 5, 6 or 15 minutes. The time clock rounding calculator shows that.
- Your payroll system’s own rounding: some systems keep more decimal places or round differently; your pay stub shows what yours does.
Minutes to decimal hours chart
Every minute of an hour, rounded half up to two places. Where the decimal never ends, the exact value is in the right-hand column: 20 minutes is 0.333… hours, written 0.33. A row with nothing in that column is exact.
| Min | Hours | Exact |
|---|---|---|
| 0 | 0.00 | exact |
| 1 | 0.02 | 0.01666… |
| 2 | 0.03 | 0.0333… |
| 3 | 0.05 | exact |
| 4 | 0.07 | 0.0666… |
| 5 | 0.08 | 0.08333… |
| 6 | 0.10 | exact |
| 7 | 0.12 | 0.11666… |
| 8 | 0.13 | 0.1333… |
| 9 | 0.15 | exact |
| 10 | 0.17 | 0.1666… |
| 11 | 0.18 | 0.18333… |
| 12 | 0.20 | exact |
| 13 | 0.22 | 0.21666… |
| 14 | 0.23 | 0.2333… |
| 15 | 0.25 | exact |
| Min | Hours | Exact |
|---|---|---|
| 16 | 0.27 | 0.2666… |
| 17 | 0.28 | 0.28333… |
| 18 | 0.30 | exact |
| 19 | 0.32 | 0.31666… |
| 20 | 0.33 | 0.333… |
| 21 | 0.35 | exact |
| 22 | 0.37 | 0.3666… |
| 23 | 0.38 | 0.38333… |
| 24 | 0.40 | exact |
| 25 | 0.42 | 0.41666… |
| 26 | 0.43 | 0.4333… |
| 27 | 0.45 | exact |
| 28 | 0.47 | 0.4666… |
| 29 | 0.48 | 0.48333… |
| 30 | 0.50 | exact |
| Min | Hours | Exact |
|---|---|---|
| 31 | 0.52 | 0.51666… |
| 32 | 0.53 | 0.5333… |
| 33 | 0.55 | exact |
| 34 | 0.57 | 0.5666… |
| 35 | 0.58 | 0.58333… |
| 36 | 0.60 | exact |
| 37 | 0.62 | 0.61666… |
| 38 | 0.63 | 0.6333… |
| 39 | 0.65 | exact |
| 40 | 0.67 | 0.666… |
| 41 | 0.68 | 0.68333… |
| 42 | 0.70 | exact |
| 43 | 0.72 | 0.71666… |
| 44 | 0.73 | 0.7333… |
| 45 | 0.75 | exact |
| Min | Hours | Exact |
|---|---|---|
| 46 | 0.77 | 0.7666… |
| 47 | 0.78 | 0.78333… |
| 48 | 0.80 | exact |
| 49 | 0.82 | 0.81666… |
| 50 | 0.83 | 0.8333… |
| 51 | 0.85 | exact |
| 52 | 0.87 | 0.8666… |
| 53 | 0.88 | 0.88333… |
| 54 | 0.90 | exact |
| 55 | 0.92 | 0.91666… |
| 56 | 0.93 | 0.9333… |
| 57 | 0.95 | exact |
| 58 | 0.97 | 0.9666… |
| 59 | 0.98 | 0.98333… |
| 60 | 1.00 | exact |
Hours and minutes add the whole hours in front: 7:20 is 7 + 0.33 = 7.33 hours.
Calculated with Punch Clock Math · rules checked October 22, 2026 · an estimate, not legal or tax advice · punchclockmath.com
Guides that explain this tool
Guide · Hours
How to Fill Out a Weekly Time Card
Fill out a weekly time card step by step: the header, each day’s in and out times, meal breaks, overnight shifts, daily and weekly totals, and signing it.
Updated · 6 min read
In-depth guide · Hours
How to Calculate Hours Worked on a Time Card
How to calculate hours worked from in and out punches: subtract, remove unpaid meal breaks, handle overnight and DST shifts, convert to decimal.
Updated · 11 min read
Page sources
Every rule above comes from these pages, read on the dates shown.