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Time Duration Calculator

Know the duration between any two time points.

Tools-Calculators-TimeDuration-Responsive

This is a tool that calculates the difference in time between a “From” (Start) time and a “To” (End Time) time. Use the three inputs for each (Hours, Minutes, and Seconds).

There’s an AM/PM toggle (checkbox) for each time.

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12 or 24 hours?

@Reader

It’s designed to work with a 12-hour time format.

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Time Vs. Duration

Is There a Difference?

“Time” refers to a specific point on the timeline (e.g. 8:00 PM today). “Duration” refers to the length between two points in time – how long something lasts.

Why Do You Use Am/pm?

12-hour format uses AM/PM to distinguish between morning and afternoon/evening times (e.g., 3:00 PM). 24-hour format represents all times using numbers from 00 to 23, without AM/PM (e.g., 15:00 is 3:00 PM). We simply went with a

Hours: 1-12
Minutes: 0-60
Seconds: 0-60

What If I Flip It?

When the “To” time is earlier than the “From” time (crossing midnight), the calculator automatically accounts for the full day in between.

Example:

Starting Time: 10:00 AM
Ending Time: 7:00 AM

Difference on the same day (ignoring date): Hours: 7 – 10 = -3 hours. Add 1 full day between Dec 31st and Jan 1st (24 hours).
Total Duration: (-3 + 24) hours = 21 hours

Duration: 21 hours

If you want to convert time units from one to the other, we also have a tool for that.