How it works
Clocking in and out across separate work shifts means you often need to add up fragmented time blocks rather than measure one continuous span. The Hours Calculator takes each shift's start time, end time, and unpaid break in minutes, converts everything to a common minute count, sums the blocks, and hands back total hours worked in both clock format (hours and minutes) and decimal format for payroll multiplication.
This matters because timesheet software and payroll systems expect decimal hours — 7.75 means "seven hours and forty-five minutes," not "seven hours and seventy-five minutes." Getting that conversion wrong underpays or overpays staff.
The formula
Total minutes = Σ((End − Start) × 60) − Σ(Break); Hours = floor(Total minutes ÷ 60); Minutes = Total minutes mod 60
Worked example
A hospitality worker logs two separate shifts on the same timesheet. Shift one runs from 09:00 to 16:45 with a 30-minute unpaid meal break. Shift two runs from 18:00 to 21:30 with no break.
Shift one raw span: 16:45 − 09:00 = 7 h 45 min
Shift one after break: 7 h 45 min − 30 min = 7 h 15 min
Shift two raw span: 21:30 − 18:00 = 3 h 30 min
Now convert each shift to minutes so they share a common unit before summing.
Shift one in minutes: (7 × 60) + 15 = 435 min
Shift two in minutes: (3 × 60) + 30 = 210 min
Shift one plus shift two: 435 + 210 = 645 min
Convert the combined minute total back into hours and minutes for the timesheet.
Hours: floor(645 ÷ 60) = 10
Remaining minutes: 645 − (10 × 60) = 45
Total hours worked: 10 hours 45 minutes
For payroll at $22 per hour, the decimal equivalent feeds directly into the gross pay calculation.
Decimal hours: 645 ÷ 60 = 10.75
Gross pay: 10.75 × $22 = $236.50
Common mistakes
| Mistake | What happens | Fix |
|---|---|---|
| Entering break in decimal hours (0.5) instead of minutes (30) | Break barely deducts, overstates hours | Always enter breaks as whole minutes |
| Forgetting overnight wrap | Night shift shows negative hours | Add 24 h to end time if it's smaller than start |
| Deducting paid rest breaks | Understates payable time | Only subtract unpaid meal breaks |
| Writing 7.45 instead of 7.75 on the timesheet | Payroll reads 7 h 27 min, not 7 h 45 min | Use the decimal output the calculator provides |
One more trap: if a shift starts at 23:00 and ends at 07:00, the raw subtraction reads −16 hours. The calculator detects this and adds 24 hours, giving the correct 8-hour overnight span — but only if the tool is built for shift work, not just daytime arithmetic.
This tool gives a timesheet estimate for personal tracking and payroll spot-checks, not certified payroll or labor-law compliance.