What is Time?
The Time Calculator adds and subtracts hours, minutes, and seconds — a surprisingly common need that's surprisingly hard to do in your head. Whether you're calculating work hours, tracking exercise duration, planning schedules, or computing time differences, this tool gives instant results.
Most people search for a time calculator when they need to: add up work hours for a timesheet, calculate total duration of multiple tasks, find the difference between a start and end time, or convert hours to minutes/seconds.
This is one of the top 10 most-searched calculator types globally because time math is awkward — 60 seconds in a minute, 60 minutes in an hour, and 24 hours in a day. Unlike base-10 calculations, time arithmetic requires carrying over at 60, which is error-prone mentally.
Need to calculate the difference between two dates instead? Use our Date Difference Calculator. For speed calculations, try our Speed Distance Time Calculator.
Formula
Time addition: Total seconds = (H1×3600 + M1×60 + S1) + (H2×3600 + M2×60 + S2) Convert back: Hours = Total ÷ 3600, Minutes = (remainder) ÷ 60, Seconds = remainder
Example — 8h 30m + 2h 45m: Time 1 = 30,600 sec Time 2 = 9,900 sec Sum = 40,500 sec = 11h 15m 0s Difference = 20,700 sec = 5h 45m 0s
Quick conversions: 1 hour = 60 minutes = 3,600 seconds 1 day = 24 hours = 1,440 minutes = 86,400 seconds 1 week = 168 hours = 10,080 minutes
How to use this Time Calculator?
1. Enter Time 1 in hours, minutes, seconds. 2. Enter Time 2 in hours, minutes, seconds. 3. See the sum (Time 1 + Time 2), difference (|Time 1 − Time 2|), and total in minutes/seconds.
Use cases: - Timesheet: add 8h30m + 7h45m + 8h15m across multiple entries - Exercise: total running time of 3 sessions - Cooking: 45m prep + 1h20m baking = total time