← All Tools / Time Calculator

Time Calculator

Add or subtract time durations, or find the difference between two clock times.

Total (HH:MM:SS)
—
Decimal Hours
—

What is a Time Calculator?

A time calculator helps you add or subtract time durations (hours, minutes, seconds) and find the difference between two specific clock times. It's useful for calculating total work hours, travel times, recipe timings, and any scenario where you need precise time arithmetic.

How to Use

  1. Add/Subtract mode: Add multiple time entries in HH:MM:SS format. The calculator sums them and shows the total in both HH:MM:SS and decimal hours.
  2. Time Difference mode: Enter a start time and end time to find the exact duration. Handles overnight times (e.g. 10pm to 6am).

Frequently Asked Questions

Convert all values to minutes, add them, then convert back. Example: 2h 45m + 1h 30m = 165 min + 90 min = 255 min = 4h 15m. Our calculator does this automatically for multiple entries.

Switch to Time Difference mode, enter your start and end times. For overnight durations (e.g. 11pm to 7am), the calculator automatically adds 24 hours to handle the midnight crossing and shows the correct 8-hour result.

Decimal time expresses time as a fraction of an hour. For example, 1h 30m = 1.5 hours, 45 minutes = 0.75 hours. Decimal hours are used for payroll calculations where hourly rates are applied: 7.5 hours at $20/hr = $150.

There are 1,440 minutes in a day (24 hours × 60 minutes), 86,400 seconds (24 × 60 × 60), and 168 hours in a week. A month averages 43,800 minutes and a year has 525,600 minutes (as in the famous Rent song).

Quick Facts

  • ✓ Add multiple time durations
  • ✓ HH:MM:SS and decimal output
  • ✓ Handles overnight durations
  • ✓ Useful for payroll & planning
  • ✓ 100% free, browser-based

Related Tools