Why payroll systems use decimal hours, and the formula to get there.
Payroll systems almost always want hours as a decimal — 7.5 instead of "7 hours 30 minutes" — because decimals are easier to multiply by an hourly rate. Converting minutes to decimal hours takes one small formula, and a handful of values come up so often that it's worth memorising them. If you just want an instant answer for a specific number, the Minutes to Decimal Hours Calculator converts as you type, in either direction.
Decimal hours = whole hours + (minutes ÷ 60). The minutes always divide by 60, never by 100, because an hour has 60 minutes, not 100 — that's the single most common source of errors here.
"7 hours 30 minutes" is easy for a person to read, but it's awkward for a spreadsheet or payroll system to multiply directly against an hourly rate, since 30 minutes isn't 30% of an hour — it's 50%. Decimal hours solve that: 7.5 hours × a rate is a single, ordinary multiplication, with no separate minutes maths required. That's why almost every payroll system, timesheet spreadsheet, and invoicing tool asks for hours in decimal form rather than hours-and-minutes.
| Minutes | Decimal hours |
|---|---|
| 5 minutes | 0.08 |
| 10 minutes | 0.17 |
| 15 minutes | 0.25 |
| 20 minutes | 0.33 |
| 25 minutes | 0.42 |
| 30 minutes | 0.50 |
| 35 minutes | 0.58 |
| 40 minutes | 0.67 |
| 45 minutes | 0.75 |
| 50 minutes | 0.83 |
| 55 minutes | 0.92 |
An employee worked 8 hours and 45 minutes. 45 ÷ 60 = 0.75, so the decimal figure is 8.75 hours.
A shift lasted 7 hours and 20 minutes. 20 ÷ 60 = 0.333..., which rounds to 0.33, so the decimal figure is 7.33 hours (most payroll systems round to two decimal places).
Suppose a week has four days worked: 7.5, 8.25, 6.75, and 8.0 hours. Adding decimals is ordinary addition — no carrying rule needed, which is part of why the format is convenient once everything is already converted.
Converting that back the other way — from 30.5 decimal hours to hours-and-minutes — just reverses the formula: take the fractional part (0.5), multiply by 60 (0.5 × 60 = 30), and that's the minutes. So 30.5 hours is 30 hours, 30 minutes.
Going the other direction uses the reverse formula: minutes = decimal fraction × 60. For example, 6.4 hours has a fractional part of 0.4; 0.4 × 60 = 24, so 6.4 hours is 6 hours and 24 minutes. This direction matters when a payroll report gives you a decimal figure but you need to communicate it back to someone as a clock-friendly duration.
Every calculator on Hourlyfy that reports a time also shows the decimal-hours version automatically — try the Hours Calculator or Time Card Calculator and check the "decimal hours" figure against the table above.
Most payroll systems round decimal hours to two decimal places, which is precise enough to represent any minute value to within a fraction of a cent at typical hourly rates. A few older or simpler systems round to the nearest quarter hour instead (0.00, 0.25, 0.50, or 0.75), which is less precise but easier to read at a glance. If your employer rounds to the quarter hour, 22 minutes would typically round down to 0.25 (15 minutes) or up to 0.50 (30 minutes) depending on the specific rounding rule in use — it's worth asking which convention your payroll system follows if the numbers on a pay stub don't seem to match a straight minutes-to-decimal conversion.
Estimates only. Not legal, tax, or payroll advice.