PE and sports day
Time sprints and relay legs, recording each runner as a lap.
Online Stopwatch for the Classroom
Time races, experiments and class challenges on a screen everyone can see. This online stopwatch shows tenths of a second and records laps with split times.
Open in full classroom screen
Free, no sign-up. Add more widgets alongside it.
How to use the online stopwatch
- 1
Press Space or Start to begin timing.
- 2
Tap Lap to record a time without stopping. Each lap shows its split time.
- 3
Press Space again to stop, then reset when you are ready for the next run.
What it does
Tenths of a second
Precise enough for close races and quick experiments.
Laps and splits
Record as many laps as you need and see the split time for each one.
Space to start and stop
Keep your eyes on the class. One key starts the stopwatch and the same key stops it.
Ways teachers use it
Science experiments
Time how long an ice cube takes to melt or a paper helicopter takes to fall, and log each trial as a lap.
Beat-the-clock challenges
How fast can the class line up or tidy the room? Time it today and try to beat it tomorrow.
Frequently asked questions
The timer counts down from a time you set. The online stopwatch counts up from zero, so use it to measure how long something takes.
Yes. Tap Lap while the stopwatch is running and each lap is listed with its split time.
Yes. It runs in any modern browser on a laptop with a projector, an interactive whiteboard or a classroom TV. On the full board, press F for full screen.
Yes. The ClassroomScreen stopwatch is free and needs no sign-up.
More free classroom tools
Dice rollerRoll up to six dice, flip a coin or pick a random number.Voice level chartShow the expected voice level and work mode in one place.Classroom scoreboardTeam scores for 2 to 6 teams, with a crown for the leader.Class reward jarA marble jar that fills toward a class goal, with confetti at the end.