How to calculate work hours

Payroll systems pay in decimal hours, not hours-and-minutes. The conversion is straightforward: take the minutes, divide by 60, and add to the hours.

For example, a shift that ends at 5:45 PM after starting at 9:00 AM is 8 hours and 45 minutes. To convert: 45 ÷ 60 = 0.75. So the shift equals 8.75 decimal hours. At a $20/hour rate, gross pay for that shift is 8.75 × $20 = $175.

A quick reference for common minute conversions:

Most US employers treat meal breaks of 30 minutes or longer as unpaid time. Short rest breaks (typically under 20 minutes) are paid under federal FLSA rules. Always subtract the unpaid portion after calculating gross shift time.

Example: clocked in at 8:00 AM, out at 5:00 PM, with a 60-minute unpaid lunch. Gross shift = 9.00 hours. Paid hours = 9.00 − 1.00 = 8.00 hours.

Watch for state nuances. California, for instance, requires a paid 10-minute rest break for every 4 hours worked, and an unpaid 30-minute meal break before the 5th hour. Some union contracts add paid wash-up time at shift end. When in doubt, ask your HR contact what gets deducted.

When the end time is earlier than the start time — common in healthcare, security, and hospitality — the shift crosses midnight. The math is the same; you just have to add 24 hours to the end time before subtracting.

Example: clocked in at 10:00 PM, out at 6:30 AM. Treat the out-time as 30:30 (6:30 + 24:00). 30:30 − 22:00 = 8 hours 30 minutes = 8.5 hours.

Daylight Saving Time also matters for overnight shifts in March and November in the US. A shift that crosses the "spring forward" cutoff is one hour shorterthan the wall clock suggests; the "fall back" shift is one hour longer.

Federal law allows employers to round punches to the nearest 5, 6 (tenth of an hour), or 15-minute increment — as long as the rounding doesn't systematically favor the employer. The most common policy is the 7-minute rule:

• Punches at minute 0–7 round down to the previous quarter hour.
• Punches at minute 8–14 round up to the next quarter hour.

A clock-in at 8:07 AM rounds down to 8:00. A clock-in at 8:08 AM rounds up to 8:15. Over time, the rounding should net out to roughly zero — if it consistently shaves time off paychecks, it violates FLSA.

Our calculator supports rounding to 5, 6, 10, or 15-minute increments, with three modes: nearest (the 7-minute rule), always round up, or always round down. Pick whichever your employer uses in their handbook.

Sarah is a non-exempt employee paid $22/hour. Her timesheet for one week:

Sarah worked 43 hours. Under federal FLSA, the first 40 are regular pay and the remaining 3 are overtime at 1.5×.

• Regular: 40 × $22 = $880.00
• Overtime: 3 × $22 × 1.5 = $99.00
• Gross pay: $979.00

• Adding minutes as if they were decimals. "8 hours and 30 minutes" is 8.5, not 8.30. This is the single most common error.
• Forgetting to subtract breaks. Always clarify which breaks are unpaid before you do the math.
• Treating overtime as separate hours. OT hours are part of total hours — they're just paid at a different rate.
• Ignoring local rules. California, Alaska, Nevada, and Colorado all have daily overtime triggers federal law doesn't.