# Time Calculator - Add Hours, Time Between & Work Hours

> Free time calculator: add or subtract hours, minutes and seconds, time between two clock times (even overnight), timesheet totals and decimal hours.

- URL: https://qilingtools.com/en/math/time-calc
- Category: Math Tools (https://qilingtools.com/en/math)
- Tags: [Math](https://qilingtools.com/en/tags/math), [Date & Time](https://qilingtools.com/en/tags/time)
- Last updated: 2026-10-26
- Price: Free, no sign-up
- Privacy: Runs locally in the browser; files are never uploaded

A time calculator for all “hours and minutes” arithmetic: add or subtract durations such as 2:45:30 and 1 h 20 min, find how long it is from 22:30 to 6:15 the next morning, total a list of timesheet entries like “1:30, 45m, 2h10m” in one go, convert 7.75 hours to 7:45:00 and back, and multiply or divide durations (three 1:45:00 lessons, or the average of a total). The work-hours tab takes a start time, end time and break for each day and returns daily hours, the weekly total and the split between regular time and overtime after 8 hours a day or 40 hours a week; add an hourly rate to get pay including overtime. Input is forgiving: 1:30, 1:30:15, 45m, 2h10m, 1.5h, 90 min, 2 hours 15 min and 2d 3:00 all work, and clock times accept 21:45 or 9:30 pm.

## How to use

1. Pick a tab: add / subtract, time between, sum durations, decimal ↔ h:m:s, multiply / divide or work hours
2. Type durations or clock times in almost any format (1:30, 2h10m, 90 min, 9:30 pm)
3. Read the result as h:mm:ss, days-hours-minutes-seconds, decimal hours, total minutes and total seconds, and copy it

## Features

- Add and subtract durations; results can exceed 24 hours or be negative
- Time between two clock times, automatically crossing midnight when the end is earlier
- Add a duration to a clock time and see the resulting time with a +1 day note
- Sum a list of durations (comma or line separated) with per-item parsing and the average
- Decimal hours ↔ h:mm:ss with a minutes-to-decimal reference table
- Multiply or divide a duration by a number, or divide one duration by another
- Weekly timesheet: start, end, breaks, night shifts, daily or weekly overtime and pay
- Runs entirely in your browser

## FAQ

### How do I convert decimal hours to hours and minutes?

Multiply the decimal part by 60: 7.75 hours → 0.75 × 60 = 45, so 7.75 h = 7 hours 45 minutes (7:45:00). To go the other way divide minutes by 60, e.g. 20 minutes = 0.3333 h and 45 minutes = 0.75 h. The Decimal ↔ h:m:s tab converts either direction and includes a 5–60 minute reference table.

### How is an overnight shift calculated?

If the end time is earlier than the start time the calculator assumes the shift crosses midnight. From 22:00 to 6:30 the next morning is 8 hours 30 minutes; the break is then subtracted to get the hours worked, and the row is marked with a 🌙.

### How is overtime worked out?

Set a daily limit (for example 8 hours) and/or a weekly limit (for example 40 hours); 0 turns a rule off. With both on, daily overtime is counted first and only the remaining regular hours count toward the weekly limit, so no hour is counted twice. Enter an hourly rate and an overtime multiplier such as 1.5 to get total pay. Check your local labour rules for the exact policy.

### Which time formats can I type?

Durations: 1:30 (1 h 30 min), 1:30:15 (h:mm:ss), 45m, 2h10m, 1d2h30m, 1.5h, 90min, 2 hours 15 min, 2d 3:00 — a leading minus subtracts. Clock times: 9:30, 21:45:10, 9:30 pm, 12:15 am or 0930. In the sum tab you can choose whether plain numbers mean hours, minutes or seconds.

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