Hours Calculator
Add up work hours, build a weekly timesheet, or find the time between two clock readings — in HH:MM and decimal hours.
Calculate
Formats accepted: 2:30, 2.5h, 150m, 90 (minutes)
| Day | Start | End | Break (min) |
|---|---|---|---|
| Mon | |||
| Tue | |||
| Wed | |||
| Thu | |||
| Fri | |||
| Sat | |||
| Sun |
How to Use the Hours Calculator
Pick the mode that matches your question. Between two times handles a single shift: type a start and end time (12-hour like 9:00 AM or 24-hour like 14:30), add any unpaid break in minutes, and the net hours appear instantly. Shifts that cross midnight are detected automatically and flagged as overnight — no need to do the "plus 24 hours" math yourself.
Add durations is for totalling scattered time entries: paste one duration per line in whatever format is handy — 2:30, 2.5h, 150m — and the tool normalizes everything. Timesheet week is the full payroll view: fill one row per day and it totals the week, splitting regular hours (the first 40) from overtime, with a one-click CSV export you can hand straight to payroll.
Adding Hours and Minutes
Adding time trips people up because minutes roll over at 60, not 100. The reliable method: convert everything to minutes first, add, then convert back.
Example: 2h 45m + 1h 30m. Convert: (2 × 60) + 45 = 165 minutes, and (1 × 60) + 30 = 90 minutes. Add: 165 + 90 = 255 minutes. Convert back: 255 ÷ 60 = 4 hours with 15 left over → 4h 15m. The calculator does this in the background every time you type, so you can sanity-check by watching the total move as you edit entries.
Calculating Hours Between Two Times
The core formula is simple subtraction — end minus start — with two wrinkles that cause most mistakes:
- Overnight shifts: if the end time is earlier than the start time, the shift crossed midnight, so add 24 hours to the end time first. 10:00 PM → 6:00 AM becomes 22:00 → 30:00 = 8 hours.
- Unpaid breaks: subtract them from the gross duration. A 9:00 AM → 5:30 PM shift is 8.5 hours gross, but with a 30-minute lunch it is 8.0 paid hours.
AM/PM mix-ups are the classic error: 12:00 PM is noon, 12:00 AM is midnight. When in doubt, use 24-hour format (13:00 instead of 1:00 PM) — it removes the ambiguity entirely.
Timesheet Example: A Full Work Week
Suppose you work Monday through Friday, 9:00 AM to 5:00 PM, with a 30-minute unpaid lunch each day:
| Day | Start | End | Break | Net hours |
|---|---|---|---|---|
| Mon | 9:00 AM | 5:00 PM | 30 min | 7.50 |
| Tue | 9:00 AM | 5:00 PM | 30 min | 7.50 |
| Wed | 9:00 AM | 5:00 PM | 30 min | 7.50 |
| Thu | 9:00 AM | 5:00 PM | 30 min | 7.50 |
| Fri | 9:00 AM | 5:00 PM | 30 min | 7.50 |
| Total | 37.50 |
Each day: 8 hours gross minus 0.5-hour lunch = 7.5 hours. Five days × 7.5 = 37.5 hours for the week — all regular time, since it is under 40. Add a Saturday shift and the calculator automatically splits anything past 40 hours into overtime, matching the standard US payroll practice of time-and-a-half after 40 hours in a week.
Decimal Hours vs HH:MM Format
Payroll systems usually want decimal hours (7.50), while humans read HH:MM (7:30) more easily. Converting between them:
- HH:MM → decimal: divide minutes by 60 and add to hours. 7:30 → 7 + 30/60 = 7.50.
- Decimal → HH:MM: multiply the decimal part by 60. 7.75 → 0.75 × 60 = 45 → 7:45.
The trap: 7.30 hours is not 7 hours 30 minutes — it is 7 hours and 18 minutes (0.30 × 60). This single confusion causes a surprising share of payroll corrections, so always double-check which format a form is asking for. The calculator shows both side by side precisely to prevent that mistake.
My saved numbers reuse them in any calculator
Save a number once — like your rent or hourly rate — then just type its name instead of the number, in any calculator here. You can also type formulas like 5000 * 1.1 right into any box.
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Frequently Asked Questions
How do I add hours and minutes?
Convert everything to minutes, add them up, then convert back: divide the total by 60 for hours, the remainder is minutes. For example, 2h 45m + 1h 30m = 165 + 90 = 255 minutes = 4h 15m. This calculator does it instantly.
How do I calculate hours worked in a week?
Add each day's shift (end time minus start time, minus unpaid breaks) across the week. Use the Timesheet mode above: enter one row per day and it totals everything, splitting regular hours (up to 40) from overtime automatically.
What is 7.5 hours in hours and minutes?
7.5 hours is 7 hours and 30 minutes. Multiply the decimal part by 60: 0.5 × 60 = 30 minutes. Going the other way, 7 hours 45 minutes = 7.75 hours.
How do I subtract time?
Convert both values to the same unit (usually minutes), subtract, then convert back. For example, 5h 20m − 2h 45m = 320 − 165 = 155 minutes = 2h 35m. Overnight shifts count forward past midnight automatically.
Can I use this as a timesheet calculator?
Yes. The Timesheet mode is built for exactly that: add a row per workday with start, end and break times, and it totals the week — showing regular vs. overtime hours and exporting a CSV you can hand to payroll.