Time calculator guides

Short, practical walk-throughs for the most common time-math jobs. Every guide leads with a direct answer, then shows worked examples you can run right here in the browser.

Guide 01

How do I add up hours and minutes?

Add up hours and minutes in one line. Type each duration like 8h 15m, join them with +, and pick a format. Free time calculator for timesheets, web and apps.

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Guide 02

How do you calculate hours worked between two times?

Calculate hours worked between two clock times. Write each time as hours and minutes from midnight, then subtract: 17h 45m - 9h 15m gives 8 Hours 30 Minutes.

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Guide 03

How do I add and subtract time durations across units?

Add and subtract time across hours, minutes, days, and weeks in one line. Type "2 days - 4h" and read the result in any format. Free, no conversion needed.

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Guide 04

How do I total the hours on a weekly timesheet?

Add up your weekly timesheet or time card hours in seconds. Type each day as hours and minutes, hit plus, and get a clean Hour Minute total. Free, in your browser.

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Guide 05

How do I multiply or split a time duration?

Multiply or split a time duration in seconds. Type "8h 15m × 3" to repeat a block or "1 day ÷ 4" to divide it evenly. Free, right in your browser.

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Guide 06

How do I convert between time units like minutes to seconds or hours to minutes?

Convert minutes to seconds, hours to minutes, seconds to hours, and milliseconds with a free time calculator. Type the duration, pick an output format, done.

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Guide 07

Convert Time to Decimal Hours

Convert hours and minutes to decimal hours for payroll. See why 8h 15m = 8.25, the 15/30/45 rule, and how to handle repeating decimals like 8.3333333.

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Guide 08

How to Calculate the Time Between Two Times

Find the time between two times by writing each clock time as a duration from midnight, then subtracting. Examples for parking, ovens, study blocks, and flights.

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Guide 09

Add Up Video and Audio Lengths (mm:ss and Milliseconds)

Total clip and track lengths in minutes and seconds, roll past an hour, and work in milliseconds. A free mm:ss calculator built for video editors and audio work.

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Guide 10

Billable Hours Calculator

Add up billable time across client sessions and convert the total to decimal hours for invoicing. Sum durations, multiply repeated tasks, and get a clean decimal.

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