Work Hours Calculator

Enter your start and end date‑times (and optional break) to see total work time.

The formula

Worked milliseconds = End − Start − (Break minutes × 60,000)
Hours = floor(total seconds ÷ 3,600) Minutes = floor((seconds mod 3,600) ÷ 60)
Decimal hours = worked milliseconds ÷ 3,600,000
Start and End
Full date and time values, so a shift that crosses midnight is handled without special treatment.
Break minutes
Unpaid break time, subtracted from the interval. Left empty it is treated as zero.
Decimal hours
The same duration expressed as a decimal, which is the format timesheets and invoices usually want.

Worked example

A shift from 08:45 to 17:20 with a 45-minute unpaid break.

7h 50m 0s worked, which is 7.83 hours.

7h 50m is 7.83 hours, not 7.50

This is the single most common payroll error, and it costs money in both directions. Minutes are sixtieths, not hundredths: 30 minutes is 0.50, 45 minutes is 0.75, and 50 minutes is 0.83. Writing 7.50 for a seven-hour-fifty-minute shift underpays by twenty minutes. The calculator shows both formats side by side precisely so the conversion is never done by hand.

Overnight shifts work because the fields take dates

Both inputs carry a date as well as a time, so a shift from 22:00 on one day to 06:00 on the next is an ordinary subtraction — no negative result, no adding 24 hours manually. Entering only times, or the same date for both ends of an overnight shift, is what produces the end-before-start error the tool rejects.

Only unpaid breaks belong in the break field

If a rest break is paid, subtracting it understates the hours you should be paid for. Put unpaid breaks in the field and leave paid ones out. Where a break is split across a shift, add the unpaid portions and enter the total in minutes.

Rounding conventions

The result is exact to the second and the decimal is shown to two places. Employers and clients often apply their own rounding to timesheets — to the nearest quarter hour, for example. Calculate the true figure here first and apply any rounding afterwards, rather than rounding each entry as you go, which compounds across a week.

Common questions

How do I convert minutes to decimal hours?

Divide by 60. Fifteen minutes is 0.25, twenty minutes is 0.33, forty minutes is 0.67, and fifty minutes is 0.83. Treating the minutes as a decimal directly — writing 7.50 for seven hours fifty minutes — is the error that most often turns up on hand-written timesheets.

Does this handle a shift that crosses midnight?

Yes. Both fields take a date as well as a time, so set the start to one day and the end to the next and the subtraction works normally. The tool only objects when the end is genuinely before the start.

Should I subtract my lunch break?

Only if it is unpaid. Enter unpaid break time in minutes and it is deducted from the total. Paid breaks are part of the hours you are owed and should be left out of the field.

Can I total a whole week with it?

Not in one step — it calculates one interval at a time. Run each shift, note the decimal hours, and add them. Adding the decimal figures is the reliable way to do it; adding hours-and-minutes strings by hand is where weekly totals usually go wrong.

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