Online Stopwatch Guide: Lap Times & Split Intervals

Track elapsed time and lap splits without a sports watch. The TetraKits online stopwatch shows centisecond precision with a scrollable lap list — free in your browser.

Overview

A stopwatch counts up from zero. Each lap records the split since the previous lap marker. Lap 1 = time since start. Lap 2 = interval between lap 1 and lap 2. Total elapsed appears alongside each split.

How to use laps

1. Click Start to begin timing.
2. Click Lap at each interval — splits appear in the list.
3. Click Start again to Pause, then resume.
4. Click Reset to clear elapsed time and all laps.

For countdowns, use the timer.

Use cases

• Running intervals: Record each lap time for 400m repeats.
• Experiments: Log reaction times and trial splits.
• Cooking: Time each stage of a multi-step recipe.