How to Calculate Hours Worked

Start by converting clock times to the 24-hour clock, so 9:15 am to 5:45 pm becomes 09:15 to 17:45. Subtract start from end to get the elapsed time — here, 8 hours 30 minutes. Deduct unpaid breaks: a 30-minute unpaid lunch leaves 8 hours. Convert minutes to decimals by dividing by 60, since payroll systems multiply decimal hours by the hourly rate. Fifteen minutes is 0.25, twenty minutes is 0.333, forty-five minutes is 0.75. Repeat for each day, then total the week.

The most common arithmetic error is treating 8 hours 30 minutes as 8.30 hours rather than 8.5. Across a year and a team, that understates pay by a meaningful amount and creates wage claims that are trivially provable from the timesheet itself.

Not all time on site is paid, and not all paid time is on site. Under US federal rules, short rest breaks of roughly five to twenty minutes are paid; bona fide meal periods of thirty minutes or more are unpaid only if the employee is genuinely relieved of duty. Eating at a desk while covering the phone is paid time. Required training, mandatory travel between job sites, and short spells of waiting for work are generally compensable, while an ordinary home-to-work commute is not.

Rounding is allowed in the US if it is neutral — to the nearest quarter hour, rounding both up and down over time so employees are not systematically shortchanged. Rounding that only ever favours the employer is unlawful, and several states, including California, have effectively ended the practice for time that can be captured precisely. Many countries prohibit rounding altogether.

Under the US Fair Labor Standards Act, non-exempt employees earn 1.5x their regular rate for hours over 40 in a workweek; there is no federal daily overtime, though California applies daily thresholds at 8 and 12 hours plus a seventh-consecutive-day rule. The regular rate is not simply base pay — non-discretionary bonuses, shift differentials and commissions must be folded in before the multiplier is applied.

Elsewhere the rules diverge sharply. The EU Working Time Directive caps the average week at 48 hours including overtime and mandates daily and weekly rest. India's state shops and establishments acts set daily caps around 9 hours with double-time overtime. The Philippines requires night-shift differentials. Employers must also keep accurate records — three years under the FLSA, and in the EU an objective, reliable system for measuring daily working time is required outright.