Why payroll uses decimal hours
Payroll systems do not use hours and minutes. They use decimal hours. That means the minutes part of your time gets divided by 60. So 7 hours and 30 minutes becomes 7.5 hours. The 30 minutes is half of an hour, and half written as a decimal is 0.5.
Here is the rule: decimal hours = hours + (minutes / 60). If you worked 7 hours and 20 minutes, the minutes part is 20 / 60 = 0.33. So your decimal hours are 7.33. If you worked 7 hours and 15 minutes, that is 7.25. If you worked 7 hours and 45 minutes, that is 7.75.
The most common mistake is typing 7.30 when you mean 7 hours and 30 minutes. In decimal form, 7.30 is 7 hours and 18 minutes. That is 12 minutes short. Over a week, that error can cost you real money. Always convert minutes to decimal before you multiply by your pay rate.
How to convert minutes to decimal and back
To go from minutes to decimal, divide the minutes by 60. For example, 45 minutes is 45 / 60 = 0.75. To go from decimal back to minutes, multiply the decimal part by 60. If you have 7.75 hours, take 0.75 x 60 = 45 minutes. So 7.75 hours is 7 hours and 45 minutes.
Here is a worked example using a full shift. You clock in at 8:07 am and clock out at 4:33 pm. You take a 60-minute unpaid break. First, find the total time from clock in to clock out. From 8:07 am to 4:07 pm is 8 hours. Then add the 26 minutes from 4:07 to 4:33. That gives 8 hours and 26 minutes. Now subtract the 60-minute break. 8 hours and 26 minutes minus 1 hour is 7 hours and 26 minutes. To get decimal hours, convert the 26 minutes: 26 / 60 = 0.43. So your decimal hours are 7.43. If you earn $20 per hour, your gross pay for the shift is 7.43 x $20 = $148.60.
This calculator does that maths for you. You can type times as 9:00, 9:00 am, 17:30 or 1730. If the end time is earlier than the start time, the calculator knows the shift crossed midnight.
Rounding rules and the tenth-of-an-hour convention
Some employers round your punch times. They might round to the nearest 5 minutes, the nearest 6 minutes (which is one tenth of an hour), or the nearest 15 minutes (a quarter hour). Under US federal rules (FLSA regulations), rounding is allowed only if it is applied consistently and does not, over time, favour the employer. This calculator rounds each shift's total when you choose a rounding rule.
The tenth-of-an-hour convention is common in some workplaces. That means each 6-minute block counts as 0.1 hours. So 7:06 becomes 7.1, 7:12 becomes 7.2, and so on. If your employer uses this, check your pay stub to see how they rounded. The calculator lets you pick that option.
Rounding to two decimals is standard for decimal hours. That is why 7:20 becomes 7.33 and not 7.3333. Two decimals are enough for payroll. If you round to more places, you might see tiny differences, but your employer's payroll system is the record.
Decimal hours chart: 60 rows
The table below shows minutes converted to decimal hours for every minute from 1 to 60. Use it to check your own time card.
| Minutes | Decimal hours |
|---|---|
| 1 | 0.02 |
| 2 | 0.03 |
| 3 | 0.05 |
| 4 | 0.07 |
| 5 | 0.08 |
| 6 | 0.10 |
| 7 | 0.12 |
| 8 | 0.13 |
| 9 | 0.15 |
| 10 | 0.17 |
| 11 | 0.18 |
| 12 | 0.20 |
| 13 | 0.22 |
| 14 | 0.23 |
| 15 | 0.25 |
| 16 | 0.27 |
| 17 | 0.28 |
| 18 | 0.30 |
| 19 | 0.32 |
| 20 | 0.33 |
| 21 | 0.35 |
| 22 | 0.37 |
| 23 | 0.38 |
| 24 | 0.40 |
| 25 | 0.42 |
| 26 | 0.43 |
| 27 | 0.45 |
| 28 | 0.47 |
| 29 | 0.48 |
| 30 | 0.50 |
| 31 | 0.52 |
| 32 | 0.53 |
| 33 | 0.55 |
| 34 | 0.57 |
| 35 | 0.58 |
| 36 | 0.60 |
| 37 | 0.62 |
| 38 | 0.63 |
| 39 | 0.65 |
| 40 | 0.67 |
| 41 | 0.68 |
| 42 | 0.70 |
| 43 | 0.72 |
| 44 | 0.73 |
| 45 | 0.75 |
| 46 | 0.77 |
| 47 | 0.78 |
| 48 | 0.80 |
| 49 | 0.82 |
| 50 | 0.83 |
| 51 | 0.85 |
| 52 | 0.87 |
| 53 | 0.88 |
| 54 | 0.90 |
| 55 | 0.92 |
| 56 | 0.93 |
| 57 | 0.95 |
| 58 | 0.97 |
| 59 | 0.98 |
| 60 | 1.00 |
Use this chart to check your pay stub. If your employer uses a different rounding rule, your decimal hours might be slightly different. The result from this calculator is an estimate. Your employer's payroll is the record.
For more help, try our hours calculator or paycheck calculator.