# Time to Seconds Calculator

Convert time to total seconds given the number of hours, minutes, and seconds. Convert a time or duration in HH:MM:SS to just seconds or to convert hours or minutes to seconds.

## How to Convert Time or Duration to Seconds

Use this formula to convert a time in HH:MM:SS form to the total number of seconds:

seconds = (hours × 3600) + (minutes × 60) + seconds

**For example,** let’s convert 3:45:30 to the number of seconds.

seconds = (3 × 3600) + (45 × 60) + 30

seconds = 10,800 + 2,700 + 30

seconds = 13,530

Check out our time to decimal calculator for similar calculations.