Why 7 hours 45 minutes is 7.75 on a timesheet
Timesheets and payroll systems often ask for hours as a decimal, so 7 hours 45 minutes becomes 7.75 hours. The conversion is one division: divide the minutes by 60 and add the result to the whole hours. The minutes are a fraction of an hour, not hundredths, so 45 minutes is 0.75 hours and not 0.45.
Hours calculatorHow many hours did I work?OpenWhy minutes are not hundredths
Clocks count minutes in sixties, while decimal numbers count in tens. Writing 7:45 as 7.45 looks tidy, but 7.45 means seven and forty-five hundredths of an hour, which is only 7 hours 27 minutes. The gap is 18 minutes on that one shift. Twenty shifts with the same error would undercount by six hours.
Each minute is 1/60 of an hour, or about 0.0167 hours. That is why the decimal form needs a real conversion rather than a copy of the digits.
The same trap catches people who write a trailing zero. 7.30 looks like 7 hours 30 minutes, but 7.30 is the same number as 7.3, which is 7 hours 18 minutes. The digits after the point are tenths and hundredths of an hour, never minutes. If a form expects a decimal, type the decimal, and check the result by converting it back.
The fix: divide the minutes by 60
Work through it in three steps:
- Write the hours and the minutes separately. Take 7 hours 45 minutes.
- Divide the minutes by 60. 45 ÷ 60 = 0.75.
- Add the result to the hours. 7 + 0.75 = 7.75.
Six minutes is exactly one tenth of an hour, because 6 ÷ 60 = 0.1. So 12 minutes is 0.2, 30 minutes is 0.5 and 48 minutes is 0.8. Learn the six-minute steps and most common values follow. The table covers the rest, rounded to two decimal places.
| Minutes | Decimal hours |
|---|---|
| 1 | 0.02 |
| 6 | 0.10 |
| 10 | 0.17 |
| 15 | 0.25 |
| 20 | 0.33 |
| 30 | 0.50 |
| 40 | 0.67 |
| 45 | 0.75 |
| 50 | 0.83 |
Some values do not end neatly. Twenty minutes is 0.3333 hours, so 0.33 is a rounded figure. Keep the full figure if the system accepts it, and round only at the end.
Here is a full week worked both ways. Each day is worked out in minutes, then converted.
| Day | Start | Finish | Break | Worked | Decimal |
|---|---|---|---|---|---|
| Monday | 08:00 | 16:30 | 30 min | 8 h 00 min | 8.00 |
| Tuesday | 08:00 | 16:45 | 30 min | 8 h 15 min | 8.25 |
| Wednesday | 07:30 | 14:00 | none | 6 h 30 min | 6.50 |
| Thursday | 09:00 | 17:20 | 45 min | 7 h 35 min | 7.58 |
| Friday | 08:00 | 13:15 | none | 5 h 15 min | 5.25 |
| Total | 35 h 35 min | 35.58 |
The week totals 2,135 minutes, which is 35 hours 35 minutes. Divided by 60, that is 35.5833 hours, shown as 35.58. Adding the rounded daily decimals gives the same 35.58 here, but that is not guaranteed. Each rounded day can be a little off, so a payroll total is safer when it is worked from the total minutes.
To check a decimal total, reverse the steps. The part after the point, 0.58, times 60 is about 35 minutes, so 35.58 means 35 hours 35 minutes. The hours calculator does the sums for a week of shifts. Enter each shift's start time, end time and any break in minutes. It shows the total as hours and minutes, and as decimal hours for payroll.
Multiplying by an hourly rate
Pay is usually the decimal hours multiplied by the hourly rate. At $18.00 an hour, 7 hours 45 minutes is 7.75 × 18 = $139.50. Entering 7.45 instead gives $134.10, which is $5.40 less than the shift is worth.
You can also split the hours into whole hours and the fraction. Seven whole hours at $18 is $126, and 45 minutes is three quarters of an hour, or $13.50. The two parts add to $139.50, the same answer in two small steps.
The hours calculator does this multiplication when you enter a rate, and rounds the pay to the cent. Overtime rates, tax and other deductions are separate steps, so the figure it gives is basic pay for the hours alone.
Rounding rules that employers use
Employers do not all record time the same way. Some pay the exact minutes. Others round each shift to the nearest tenth of an hour, which is six minutes, or to the nearest quarter hour. Some round start and finish times separately. The rule is set by the employer, and sometimes by a contract, so check how your own time records are rounded before you assume the totals are exact. If the rule is unclear, ask whoever runs payroll to show you one shift worked out from start to finish, with any rounding written down.
Rounding each shift before adding can move the total. Two shifts of 7 hours 20 minutes make 14 hours 40 minutes, which is 14.67 hours. Rounding each shift to one decimal place first gives 7.3 + 7.3 = 14.6 hours. That is 0.07 hours short, or about $1.20 at $18 an hour.
Edge cases
- Overnight shifts. A finish time earlier than the start time means the shift ends the next day. A shift from 22:00 to 06:30 is 8 hours 30 minutes, or 8.5 hours. The overnight shift guide covers the counting in more detail.
- Breaks. Take the break off in minutes before you convert. An 8 hours 30 minute shift with a 30 minute break taken off is 8 hours, or 8.0 decimal hours.
- Seconds. Some time clocks record seconds. One second is 1/3600 of an hour. Timesheets usually drop or round them, so follow what your employer's system does.
- Forms with two boxes. Some forms ask for hours in one box and minutes in another. Put the minutes in the minutes box and leave the decimal out. Only use the decimal where the form asks for one.
