Time Calculator

Add or subtract two time durations in HH:MM:SS format. Useful for timesheet calculations, race splits and cumulative video-runtime.

How it works

Both inputs are parsed into total seconds. We add or subtract, then reformat the result as HH:MM:SS.

Key features

• HH:MM:SS input format
• Add and subtract operations
• Handles negative results (for subtraction)
• Displays result as seconds, minutes and hours too

Common use cases

Pro tips

• ◆Use leading zeros (00:05:00) for consistency but the parser accepts 5:00 too.

Common mistakes to avoid

• ✕Adding times as if they were decimals — 1:30 + 1:30 = 3:00, not 2:60.

Frequently asked questions