Tool To Calculate Hours Worked

Most paycheck errors come from a surprisingly simple place: the gap between when the clock says you worked and what actually gets paid. Unpaid breaks, rounding rules, and overtime thresholds all quietly chip away at the number before it becomes your paycheck. Knowing your exact hours before payday gives you the one number you need to dispute anything — or confirm everything is correct.

The calculation starts with the raw span between start and end times, converted into total minutes. Any break duration you enter gets subtracted, since most employers treat break time as unpaid. The resulting net minutes are divided by 60 to get decimal hours — so 8 hours and 30 minutes becomes 8.5 hours, not 8.3. That decimal format is what payroll software uses, and it is what this calculator returns.

Overtime is handled separately. Hours up to your threshold (usually 8 per day) are classified as regular hours. Any hours beyond that count as overtime and can be multiplied by your overtime rate — usually 1.5 — to calculate additional earnings. The split matters because your employer pays regular and overtime rates independently, and a single missed hour of overtime can mean a meaningful underpayment over the course of a week.

Use this calculator before submitting a timesheet, after receiving a paycheck that looks off, or any time you are billing a client hourly and want to confirm the number before sending an invoice. It handles single-shift calculations cleanly and gives you the exact decimal figure payroll systems use.

It is also useful during job negotiations to quickly convert a proposed salary into an effective hourly rate — or to check whether accepting mandatory overtime at a lower base rate actually works out in your favor compared to a higher straight-time rate.

This calculator is not appropriate for tracking cumulative weekly hours across multiple shifts — it is designed for one shift at a time. For weekly overtime calculations, you would need to sum multiple shifts manually and compare the total against a 40-hour threshold. It also does not account for shift differentials, holiday pay multipliers, or tip credits, which are employer-specific policies that sit outside the math this tool handles.

The most common mistake is forgetting to account for breaks. A worker who clocks 9 hours but takes a 45-minute unpaid lunch has actually worked 8.25 paid hours. Entering the raw shift duration without subtracting breaks inflates your expected pay and makes real paychecks look like underpayments when they may not be.

The second mistake is using 12-hour clock times without AM or PM designations, then being confused when the result looks wrong. Entering 3:00 instead of 3:00 PM when you ended after noon can produce a result that subtracts your evening end time from your morning start — or triggers the midnight correction incorrectly. Use either consistent 24-hour format or always include AM or PM when using 12-hour times.

The third mistake is assuming the federal 40-hour weekly overtime rule applies everywhere. In California, daily overtime kicks in after 8 hours in a single shift, and double time begins after 12. If you are in a state with daily overtime rules and your employer is using the 40-hour threshold, you may be systematically underpaid on long shifts. This calculator lets you set your own threshold so you can check both scenarios.

The core calculation is straightforward: convert both times to minutes since midnight, subtract start from end (adding 1,440 minutes if the result is negative to handle midnight crossings), then subtract break minutes. Divide by 60 to get decimal hours.

For pay estimation: regular pay equals regular hours multiplied by your hourly rate. Overtime pay equals overtime hours multiplied by your hourly rate multiplied by your overtime multiplier. Total shift pay is the sum of both. Written out: Total Pay = (min(hours, threshold) x rate) + (max(0, hours - threshold) x rate x multiplier).

Decimal hours are the standard payroll format. One hour and 45 minutes is 1.75 hours, not 1.45. This is where many manual calculations go wrong — people treat the colon in 1:45 as a decimal point. The calculator avoids this by converting everything to minutes first before dividing.

Most time-tracking software uses bankers rounding or truncation to the nearest quarter-hour, which systematically favors the employer when applied consistently. If your employer rounds to the nearest 15 minutes, a shift that runs 7 hours and 8 minutes gets paid as 7.0 hours — that is 8 minutes of free work per shift. Over 250 working days, it adds up to 33 hours of unpaid labor annually. This calculator uses exact minutes, so you can compare it against your rounded paycheck to quantify the gap.