Time Calculatorby Cardamon

How do I subtract lunch break from work hours?

Dmitrii Kargashin By Dmitrii Kargashin · Updated July 2026

Subtract lunch break from work hours by typing the full shift span, then removing each unpaid break with a minus sign: 9h - 45m returns 8 Hours 15 Minutes. Chain more minuses for extra breaks, like 8h 30m - 30m - 15m, and pick a result format such as Hour Minute or decimal Hour.

An 8:30 to 17:30 shift looks like nine hours on paper, but 45 minutes of it is an unpaid lunch, so only 8 hours 15 minutes counts as work. Doing that subtraction by hand means a borrow across the hour boundary, and a second rest break makes the borrow worse. This calculator takes the whole line at once: type the shift span, put a minus sign before every unpaid break, and read the paid total in the format your payroll expects.

Step by step

  1. Start with the full shift span

    Write the whole clock-in to clock-out span as one duration: a nine hour day is 9h, an eight-and-a-half hour day is 8h 30m. If you only know the clock times, subtract them in the same line, so 17h 30m - 8h 30m returns 9 Hours to deduct from.

  2. Put a minus sign before every unpaid break

    Deduct the lunch with a minus: 9h - 45m leaves 8 Hours 15 Minutes of paid time. Chain another minus for each extra break, so a half-hour lunch plus a 15 minute rest becomes 8h 30m - 30m - 15m. The calculator borrows across the hour boundary for you.

  3. Chain the whole week on one line

    Alternate plus and minus to net out every day at once. Each plus adds a shift span and each minus removes that day's break: 9h - 45m + 8h 30m - 30m + 9h - 45m covers three days and three lunches and returns 24 Hours 30 Minutes.

  4. Pick the format your payroll expects

    Hour Minute reads like 8 Hours 15 Minutes. Switch to Hour when payroll wants a decimal to multiply by a pay rate: the same 9h - 45m shows 8.25 Hours. One expression feeds both views, so change the picker instead of retyping.

Worked examples

9h - 45m=8 Hours 15 Minutes

A nine hour shift span with a 45-minute unpaid lunch deducted.

8h 30m - 30m - 15m=7 Hours 45 Minutes

One shift minus a half-hour lunch and a 15-minute rest break, chained with two minus signs.

9h - 45m + 8h 30m - 30m + 9h - 45m + 8h - 30m + 9h 15m - 45m=40 Hours 30 Minutes

A five-day week on one line: each plus adds a shift span, each minus removes that day's unpaid break.

9h - 45m=8.25 Hours

The same shift as decimal hours, ready to multiply by an hourly pay rate.

Try it yourself

Show result as
Try

Type hours, minutes, days, weeks, months, years, or seconds, as full words or shorthand (h m d w), with + - * /. Pick how the answer reads with Show result as up top. It all runs in your browser. Drag the card’s right edge to make it wider.

Common questions

Do I subtract paid breaks too?

No. Deduct only unpaid time. If your employer pays for a 15 minute rest break, leave it inside the span and remove the unpaid lunch alone: 8h 30m - 30m returns 8 Hours of paid time. Check your contract for which breaks count as unpaid.

I only have clock-in and clock-out times. Can I still deduct the break?

Yes, in one line. Write each clock time as hours and minutes from midnight, then chain the subtraction: an 8:30 to 17:15 shift with a 45 minute lunch is 17h 15m - 8h 30m - 45m, which returns 8 Hours.

How do I deduct breaks from a whole week of hours?

Chain the days with plus signs and the breaks with minus signs on a single line. 9h - 45m + 8h 30m - 30m + 9h - 45m nets out three days at once and returns 24 Hours 30 Minutes. Extend the same pattern to five days.

What if the break is bigger than the minutes on the clock?

The calculator borrows from the hour. 9h 15m - 30m returns 8 Hours 45 Minutes, with the borrow across the 60 minute boundary handled for you, so the minutes column never goes negative.

Payroll admins and hourly workers use it to strip unpaid lunches and rest breaks from each shift before the hours reach the pay run.

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