The Hours Calculator works out the span between a start and end time, subtracts your break, and reports the result as hours and minutes and as decimal hours, with gross pay if you enter an hourly rate. It handles overnight shifts, unpaid breaks, and the payroll question behind most of its use: how many hours, exactly, is this shift?
How It Works
Both times are read on a 24-hour clock. If the end time is earlier than the start time, the shift is treated as crossing midnight and 24 hours are added to the end. Break minutes are subtracted (and rejected if they exceed the shift). Decimal hours are total minutes divided by 60, shown to two decimals, and gross pay is decimal hours multiplied by your rate.
Parameters
| Input | Required | Meaning | |---|---|---| | Start time | Yes | Shift start, HH:MM | | End time | Yes | Shift end; earlier than start means overnight | | Break minutes | No | Unpaid break to subtract | | Hourly rate | No | Enables the gross pay result |
Worked examples
A standard day, 09:00 to 17:30 with a 30-minute break: the span is 8 hours 30 minutes, minus the break gives exactly 8 hours 0 minutes = 8.00 decimal hours, and at 176.00**. An overnight shift, 22:00 to 06:00 with the same break: the end rolls past midnight, the span is 8 hours, and the paid time is 7 hours 30 minutes = 7.50 hours. These two cases cover the calculator's entire personality: the midnight roll is the one most home-made spreadsheets get wrong, turning a night shift into a negative duration.
Decimal hours, rounding, and payroll
Payroll runs on decimals, and the conversion is where small errors live: 7 hours 45 minutes is 7.75 hours, not 7.45, and 20 minutes is 0.33, not 0.20. Multiply minutes by 1/60 and keep two decimals. Timesheet rounding is a policy, not a law of arithmetic: many employers round to the nearest quarter hour (the 7/8-minute rule in US practice), and a calculator like this one gives the exact figure your rounding policy then adjusts. Over a month of shifts, the difference between exact and casually rounded times is real money in one direction or the other, which is why the exact number is worth having before the policy number.
A week of shifts, and the overtime edge
For a full week, run each day and add the decimal hours; five 8.00-hour days total 40.00, the threshold beyond which US federal rules generally require overtime premium for non-exempt employees (state rules and union agreements vary, and daily overtime exists in some jurisdictions). The calculator gives you the honest total; classifying hours into regular and overtime, with their different rates, is the job of the Overtime Calculator on this site, which takes the same decimal-hours thinking further. Shift differentials for nights and weekends are likewise a rate question layered on top of the hours computed here.
Limitations
The calculator measures one span per run: it does not split a shift at midnight for two pay periods, apply rounding policies, classify regular versus overtime hours, model multiple breaks (add them and enter the total), or know your jurisdiction's labour rules. Times are taken as entered on a single shift under 24 hours. Gross pay is pre-tax and before any premium rates.
Frequently Asked Questions
How do I enter an overnight shift?
Enter the times as they occur (start 22:00, end 06:00). Because the end is earlier than the start, the calculator adds 24 hours to the end automatically and flags that the shift crosses midnight.
Why is my break rejected?
The break exceeds the shift's total span. Check the times first; a break error usually means the end time was entered in 12-hour thinking (17:30 entered as 05:30 turns a day shift into a 20-hour span or a negative one).
What decimal is 45 minutes?
0.75 hours. The conversion is minutes divided by 60: 15 minutes is 0.25, 30 is 0.50, 45 is 0.75, and any other count rounds to two decimals, so 20 minutes is 0.33.