Time Calculatorby Cardamon

Overtime Calculator: Hours Over the 40-Hour Week

Dmitrii Kargashin By Dmitrii Kargashin · Updated July 2026

An overtime calculator subtracts the standard week from your total hours worked. Type 43h 45m - 40h and the result is 3 Hours 45 Minutes of overtime. For daily overtime, subtract 8h from the shift. Switch the format to the single "Hour" option to read the same overtime as 3.75 Hours for pay math.

Overtime is what remains after the standard week comes out of your total hours. Under the US federal rule the threshold is 40 hours per week, so the math is one subtraction: total worked minus 40h. The catch is that timesheet totals arrive in hours and minutes, and subtracting 40 from 43h 45m by hand invites a borrow slip at the end of a pay period. Type the subtraction into the calculator instead, read the overtime in hours and minutes for the record, then switch to decimal hours when payroll needs a number to multiply.

Step by step

  1. Total the week and subtract 40h in one line

    Add each day's shift with plus signs, then append - 40h to the same line: 8h 30m + 9h 15m + 8h + 9h + 9h - 40h. The calculator totals the week to 43h 45m, takes off the standard 40 hours, and returns 3 Hours 45 Minutes of overtime in one pass.

  2. Start from a weekly total if you have one

    If the timesheet already shows the week as one number, type it as a duration and subtract: 43h 45m - 40h gives 3 Hours 45 Minutes. A negative answer means the week stayed under 40 hours, so there is no weekly overtime to pay.

  3. Check daily overtime against an 8-hour day

    Some states, California among them, count overtime per day once a shift passes 8 hours. Subtract the threshold from the single shift: 9h 30m - 8h gives 1 Hour 30 Minutes. Run the same subtraction on each long day, then add the results with plus signs.

  4. Read the overtime as decimal hours for pay

    Switch the result format to the single "Hour" option and 43h 45m - 40h reads as 3.75 Hours. Payroll multiplies that decimal by 1.5 times the hourly rate for time and a half. The calculator computes the hours; the currency step belongs to your payroll system.

Worked examples

43h 45m - 40h=3 Hours 45 Minutes

A 43 hour 45 minute week minus the standard 40-hour week leaves the overtime.

8h 30m + 9h 15m + 8h + 9h + 9h - 40h=3 Hours 45 Minutes

Five daily shifts totaled and the standard week subtracted in one line.

43h 45m - 40h=3.75 Hours

The same overtime as a decimal, ready for the 1.5x rate multiplication in payroll.

9h 30m - 8h=1 Hour 30 Minutes

Daily overtime: a 9 hour 30 minute shift measured against an 8-hour day.

3h 45m * 1.5=5.625 Hours

Time and a half as duration math: multiplying the 3.75 overtime hours by 1.5 gives the equivalent straight-time hours.

Try it yourself

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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

How do I calculate my overtime hours for the week?

Subtract the standard 40-hour week from your total hours worked. Type 43h 45m - 40h to get 3 Hours 45 Minutes, or build the total and the subtraction into one line: 8h 30m + 9h 15m + 8h + 9h + 9h - 40h returns the same answer.

What happens if I worked under 40 hours?

The subtraction goes negative. 38h 30m - 40h returns -1 Hours -30 Minutes, meaning the week fell 1 hour 30 minutes short of the threshold, so there is no weekly overtime. Daily overtime can still apply if a single shift ran past 8 hours.

How does the overtime number turn into time-and-a-half pay?

Read the overtime in the single "Hour" format to get a decimal like 3.75 Hours, then payroll multiplies that by 1.5 times the hourly rate. The calculator works in hours only. To see the time itself scaled, multiply the duration: 3h 45m * 1.5 gives 5.625 Hours.

Does daily overtime work the same way?

Yes, with an 8h threshold per shift in place of 40h per week. Subtract it from each day: 9h 30m - 8h gives 1 Hour 30 Minutes, which reads as 1.5 Hours in the decimal "Hour" format. Swap in - 12h where double-time rules start at 12 hours.

Payroll admins and hourly workers subtract the 40-hour standard week from a timesheet total to see the overtime hours owed at time and a half.

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