About

Payroll errors cost U.S. businesses roughly $7 billion annually. Most stem from manual hour-counting mistakes: forgotten breaks, mishandled overnight shifts, or rounding errors that compound over pay periods. This calculator converts raw clock-in/clock-out pairs into precise decimal hours using minute-level arithmetic. It accounts for cross-midnight shifts automatically (when t_end < t_start, the engine adds 1440 min to normalize the interval). Break durations are subtracted per entry before aggregation.

The tool computes net working time as H_net = n∑i=1(t_end,i − t_start,i − b_i). Overtime is flagged against a configurable daily threshold (default 8 h). Gross pay is derived by multiplying net hours by your hourly rate. Note: this tool does not handle jurisdiction-specific overtime multipliers (time-and-a-half, double-time) or split-shift premiums. Apply those rules to the overtime figure manually.

Formulas

The net working time for each entry is computed by converting clock times to minutes, handling overnight rollover, and subtracting the break duration.

H_net = n∑i=1 t_end,i − t_start,i − b_i60

Where t_end,i and t_start,i are in minutes since midnight. If t_end < t_start, the engine applies: t_end = t_end + 1440. The variable b_i is break duration in minutes.

OT = max(0, H_net − T)

Where T is the overtime threshold in hours (default 8.0). Gross pay calculation:

P = H_net × R

Where R is the hourly rate in the user's currency. For decimal hour conversion: 7 h 45 min = 7.75 decimal hours (minutes ÷ 60).

Reference Data

Scenario	Start	End	Break	Gross Hours	Net Hours	Notes
Standard day shift	09:00	17:00	30 min	8.00 h	7.50 h	Typical office schedule
Early morning shift	06:00	14:00	30 min	8.00 h	7.50 h	Manufacturing / warehouse
Overnight shift	22:00	06:00	45 min	8.00 h	7.25 h	Crosses midnight
Short part-time	10:00	14:00	0 min	4.00 h	4.00 h	No break required under 6 h (US FLSA)
Extended shift (12 h)	07:00	19:00	60 min	12.00 h	11.00 h	Healthcare / emergency
Split shift (AM block)	08:00	12:00	0 min	4.00 h	4.00 h	Enter each block as separate entry
Split shift (PM block)	16:00	20:00	0 min	4.00 h	4.00 h	Combined: 8.00 h net
US FLSA standard week	Mon - Fri		150 min	40.00 h	37.50 h	Overtime threshold: 40 h/week
EU Working Time Directive	Average week		-	48.00 h max	-	Maximum average over 17 weeks
Freelancer day	09:30	18:15	45 min	8.75 h	8.00 h	Billable hours tracking
Minimum rest (EU)	-		-	-	-	11 consecutive hours rest per 24 h
US Federal overtime rate	-		-	-	-	1.5× base rate after 40 h/week
California daily OT	-		-	-	-	1.5× after 8 h/day, 2× after 12 h
Lunch break (US FLSA)	-		30 min	-	-	Not federally required but common standard
UK statutory break	-		20 min	-	-	Required if shift > 6 h

Frequently Asked Questions

When the end time is earlier than the start time (e.g., start 22:00, end 06:00), the calculator adds 1440 minutes (24 hours) to the end time before computing the difference. This yields the correct duration of 8 hours. No manual adjustment is needed.

7 hours and 45 minutes equals 7.75 decimal hours because 45 ÷ 60 = 0.75. Payroll systems typically require decimal hours for wage multiplication. The calculator displays both formats to prevent conversion errors.

No. The calculator reports raw overtime hours (time exceeding the threshold T). Overtime multipliers vary by jurisdiction: US FLSA mandates 1.5× after 40 h/week, California adds 2× after 12 h/day. Apply the applicable multiplier to the overtime figure manually when computing final pay.

Yes. Add each block as a separate time entry with its own start and end time. The calculator sums all entries. For example, 08:00 - 12:00 and 16:00 - 20:00 yields 8.00 net hours. Set break to 0 on entries where the break is already represented by the gap between blocks.

The calculator validates each entry and rejects it with an error toast. A break of 60 minutes on a 45-minute shift produces negative net time, which is logically invalid. Correct the break value before recalculating.

Results are displayed to two decimal places using standard rounding (half-up). For a 7 h 20 min shift: 20 ÷ 60 = 0.3333..., displayed as 7.33 h. Over a full pay period this rounding can accumulate to ±1 - 2 minutes. For payroll-critical applications, verify totals against your time clock's raw minute count.