Home›Utility Tools›Time Duration Calculator
Time Math

Time Duration Calculator

Find the exact duration between two times of day, or add/subtract hours and minutes to a starting time — handy for shift scheduling, timesheets, and time math.

Advertisement

Time Calculation

Result


Enter times to calculate duration
⚠️

Disclaimer: This calculator handles time-of-day math within a single 24-hour cycle (with automatic overnight wraparound for elapsed-time mode). For multi-day date/time spans, use the Date Calculator or Day Counter tool instead.

About the Time Duration Calculator

This tool solves two common time-math problems: finding the elapsed time between a start and end clock time (e.g. for timesheets or shift lengths), and adding or subtracting a duration from a starting time (e.g. "what time is 2h 30m from now?").

Overnight Handling

When calculating elapsed time, if the end time is earlier than the start time, the calculator assumes the end time falls on the next day — correctly handling overnight shifts (e.g. 22:00 to 06:00 = 8 hours).

Common Uses

Useful for calculating work shift lengths, timesheet hours, meeting durations, cooking/baking timers, and any scenario where you need precise time-of-day arithmetic.

Frequently Asked Questions

If your end time is earlier than your start time (e.g. start 22:00, end 06:00), the calculator assumes the end time occurs the next day and correctly computes an 8-hour duration rather than a negative one.
This tool is for time-of-day math within roughly a 24-hour window. For durations spanning multiple calendar days (like project timelines), use a Date Calculator or Day Counter tool instead.
The calculator wraps around midnight automatically — subtracting past 00:00 rolls back into the previous day's time, similar to how a 24-hour clock behaves.
No, this tool works with plain clock times regardless of time zone. For converting a time between different time zones, use the Time Zone Calculator instead.
Advertisement