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Time Duration Calculator

Add, subtract and average durations written as 1h 30m, 90:00 or 1:30:00.

A duration calculator adds, subtracts or averages spans of time written in any common form — 1h 30m, 1:30:00, 90m or a bare number of minutes. The result is shown as HH:MM:SS, in words, as decimal hours for timesheets, and as an ISO 8601 duration.

Runs in your browser
Privacy
Runs entirely in your browser — nothing is uploaded
Cost
Free, unlimited, no sign-up

Frequently asked questions

Why do timesheets use decimal hours?

Because payroll multiplies hours by a rate, and 7 hours 30 minutes cannot be multiplied directly. As 7.5 it can. That is why converting between the two is the most common timesheet operation there is.

How to use the time duration calculator

  1. 1Enter or paste your durations.
  2. 2Choose the calculate.
  3. 3Choose the show as.
  4. 4The result appears immediately — copy or download it.

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Put the working time duration calculator on your own site. It runs in your visitors' browsers exactly as it does here — free, no account, nothing uploaded.

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