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Time Calculator

Add and subtract hours, minutes and seconds without base-60 mistakes.

Add or subtract durations

First duration
Second duration

—

Multiply or divide a duration

Duration

—

Convert a duration

Payroll systems want decimal hours — 7 hours 45 minutes is 7.75, not 7.45.

—Decimal hours
—Total minutes
—Total seconds
—Days

Quick Tool Overview

The Time Calculator adds and subtracts durations in hours, minutes and seconds with the carry done properly. Time is base 60, not base 10, so 1:45 plus 1:30 is 3:15 rather than 2:75 — and that carry is exactly where hand calculations go wrong.

What it does
Adds, subtracts, multiplies and divides durations
You give it
Durations in hours, minutes and seconds
You get back
The answer in clock format and in decimal hours
Best for
Timesheets, billing, video editing and project tracking
Calculators Free, unlimited use No sign-up Runs in your browser

About the Time Calculator

Add or subtract durations in hours, minutes and seconds and get a properly carried answer. Time is base 60, not base 10, so 1:45 plus 1:30 is 3:15 rather than 2:75, and that carry is exactly where hand calculations go wrong.

The calculator also multiplies and divides a duration, which is what you need for billing a rate against logged time or splitting a task across people. A converter alongside it moves between the clock format and decimal hours, since payroll systems almost always want decimal: seven hours and 45 minutes is 7.75 hours, not 7.45, and that difference has cost people real money on timesheets.

Key features of the Time Calculator

Base-60 carry handled

Minutes and seconds roll over correctly, which is the single most common manual error with time.

Multiply and divide a duration

What you need for billing a rate against logged time, or splitting a task across people.

Decimal hours conversion

Seven hours and 45 minutes is 7.75 hours, not 7.45 — a difference that has cost people real money on timesheets.

Both formats shown

Clock format for reading and decimal for payroll, side by side.

Chain several durations

Add up a list of times in one go rather than two at a time.

How to use the Time Calculator

  1. 1

    Enter your durations

    Type hours, minutes and seconds into each row. Values above 60 are carried automatically.

  2. 2

    Choose an operation

    Add or subtract the durations, or multiply and divide a single duration by a number.

  3. 3

    Read both formats

    The answer is shown in hours, minutes and seconds and as decimal hours for timesheets.

Frequently asked questions

Because minutes and seconds run in base 60. Adding 1:45 and 1:30 as decimals gives 2.75, but the correct answer is 3 hours 15 minutes, since 75 minutes carries an hour.

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