Hours between times — Quick answer
Subtract the start from the end in minutes, then convert to hours.
minutes = (end − start) [+1440 if overnight] − break · hours = minutes ÷ 60
Worked example: 9:00 → 17:30 = 510 min = 8.5 hours (8:30).
Examples
| Start → End | Break | Hours |
|---|
| 9:00 → 17:30 | 0 | 8.50 (8:30) |
| 9:00 → 17:30 | 30 | 8.00 (8:00) |
| 22:00 → 06:00 | 0 | 8.00 (8:00) |
Decimal hours suit pay; H:MM matches the clock.
Standards & method
✓ Independently verified 12 July 2026- Governing standard
- ISO 8601
- Clauses applied
- ISO 8601 date and time representation · proleptic Gregorian calendar · the leap-year rule (divisible by 4, except centuries not divisible by 400)
- Core formula
total hours = Σ durations, converted between h:mm and decimal- Why this matters
- 7.5 hours is 7h 30m, not 7h 50m. Decimal hours and h:mm are different representations and mixing them is the most common payroll error there is.
- Independently verified
- 12 July 2026 — Re-derived from the governing standard and checked numerically against worked reference cases from the standard itself — not merely tested for “returns a number”.
Results are for guidance. Verify against the current edition of the governing standard and have a qualified professional review before use in practice.
This hours calculator finds the time between a start and end time. It converts each to minutes, subtracts, adds 24 hours if the shift runs overnight, and takes off any break. The answer comes in decimal hours (good for pay) and H:MM (good for the clock).
Reviewed: June 20, 2026 · Author: Naveen P N, Founder — AI Calculator · Verified against: minute arithmetic, recomputed in code.
How it works
Each clock time becomes minutes from midnight (9:00 → 540, 17:30 → 1050). Subtract start from end; if the result is negative the shift crossed midnight, so add 1440. Subtract the break, then divide by 60 for decimal hours, or split into whole hours and leftover minutes for H:MM.
Worked examples
A 9-to-5:30 day:
The same day with a 30-minute lunch:
An overnight shift 22:00 to 06:00:
So a 9:00–17:30 day is 8.5 hours, 8.0 after a half-hour break, and a 22:00–06:00 night shift is also 8.0 hours once the overnight wrap is handled.
Frequently Asked Questions
How do I calculate hours between two times?⌄
Minutes from midnight, end − start, ÷ 60. 9:00→17:30 = 510 min = 8.5 h (8:30).
How does it handle overnight?⌄
If end < start it adds 24 h. 22:00→06:00 = 8 h, not negative.
Decimal hours vs H:MM?⌄
8.5 (for pay × rate) vs 8:30 (clock format). Both are shown.
How do I subtract a break?⌄
Enter break minutes; it's deducted. 8.5 h − 30 min = 8.0 h.
Can it span multiple days?⌄
It handles one overnight wrap. For dates across days, use a date difference calculator.