Elapsed time
Elapsed time is the total time since the stopwatch started, minus any time it was stopped. Use it for the final result.
Stopwatch
Free online stopwatch with lap timing, split times, and millisecond precision. Perfect for sports, cooking, and productivity.
00:00.00
Space Start/Stop · L Lap · R Reset
Lap Times
| Lap # | Lap Time | Split Time |
|---|
Stopwatch
A stopwatch measures elapsed time from a specific starting point. Unlike a countdown timer, which counts down to zero, a stopwatch counts upward indefinitely, making it ideal for measuring how long something takes.
The mechanical stopwatch was invented in 1776 by Jean-Moys Pouzait, a Swiss watchmaker. Early stopwatches were used primarily for astronomical observations and horse racing. The modern split-second chronograph, which can record multiple elapsed times simultaneously, was developed in the 19th century and became standard equipment in competitive sports.
Today, digital stopwatches offer precision that mechanical devices cannot match. Professional sports timing systems can measure intervals down to one-thousandth of a second. At the Olympic Games, fully automatic timing (FAT) systems use high-speed cameras shooting up to 2,000 frames per second along with pressure-sensitive starting blocks and electronic touchpads in swimming pools. The photo-finish camera captures a continuous strip image of the finish line, allowing officials to determine the exact moment each competitor crosses. This technology settled the famous 2008 Olympic 100m butterfly final, where Michael Phelps won by just one-hundredth of a second.
Stopwatches are indispensable in athletics. Coaches use them to time sprints, laps, and intervals during training. In swimming, lap splits help athletes and coaches analyze pacing strategy and identify where time can be gained or lost. In motorsports, lap times are critical for evaluating car performance, tire wear, and driver consistency. Formula 1 teams analyze timing data down to thousandths of a second across every sector of a circuit to find fractions of performance gain.
The use of stopwatches in industrial settings has a long and influential history. In the early 20th century, Frederick Winslow Taylor pioneered "scientific management" by using stopwatches to measure how long factory tasks took, then redesigning workflows to eliminate wasted motion. While Taylor's methods were controversial — workers often resented being timed — the basic approach of time studies remains fundamental to manufacturing, logistics, and process engineering today.
Beyond sports and industry, stopwatches have numerous practical applications. Scientists use them to measure the duration of experiments and reactions. In cooking, a stopwatch can track how long a sauce has been reducing or how many minutes eggs have been boiling. Musicians use them to check tempos during rehearsals, and public speakers time their presentations to stay within allotted slots.
For practical timing, the key is not just precision but consistency. Decide what counts as the start, what counts as the finish, and when you will mark laps. A speaker might mark the end of each section, a runner might mark each lap, and an operations team might mark every handoff or status change.
Our online stopwatch provides millisecond precision and a clean, easy-to-read display. The lap feature lets you record multiple intervals without stopping the main timer, which is useful for tracking splits during a run or timing multiple tasks in sequence. The split time shows the total elapsed time at the moment you pressed the lap button, while the lap time shows the duration of just that individual lap.
You can use the stopwatch in fullscreen mode for a large display that is easy to see from a distance. Whether you are timing a workout, conducting an experiment, or just curious how long something takes, this stopwatch is ready when you are.
FAQ
How accurate is this online stopwatch?
It is suitable for everyday timing, practice, workouts, cooking, and informal lap comparisons. It should not be used as the official timing device for competitive sports, records, compliance checks, or safety-critical procedures.
What is the difference between lap time and split time?
Lap time is the duration of a single interval between two lap marks. Split time is the total elapsed time from the start to each lap mark. For example, if you record a lap at 1:00 and another at 2:30, the split times are 1:00 and 2:30, while the lap times are 1:00 and 1:30.
Can I record laps while the stopwatch is running?
Yes. Press the Lap button while the stopwatch is running to record the current time without stopping the main timer. Each lap is recorded and displayed in a list below.
Does the stopwatch keep running if I switch tabs?
Yes. For best results, keep the stopwatch visible when you are actively marking laps or stopping at a precise moment.
Who invented the stopwatch?
The first stopwatch is generally attributed to Jean-Moys Pouzait, a Swiss watchmaker, in 1776. Modern chronographs with split-time capabilities were developed throughout the 19th century.
What is a good use for the lap feature?
The lap feature is useful for any activity where you need to track multiple intervals. Runners use it to time each lap around a track, coaches use it to compare performance across repetitions, and it can also be used to time stages of a multi-step process.
How does photo-finish timing work at the Olympics?
Photo-finish systems use a special camera aligned with the finish line that captures a continuous vertical strip image at up to 2,000 frames per second. Instead of taking normal photographs, it builds a composite image where the horizontal axis represents time. This allows officials to determine the exact moment each competitor crosses the line, to a precision of one-thousandth of a second. Combined with pressure-sensitive starting blocks and electronic touchpads (in swimming), this system provides indisputable timing results.
What is the difference between a stopwatch and a chronograph?
A stopwatch is a standalone timekeeping device designed solely to measure elapsed time. A chronograph is a watch that includes stopwatch functionality alongside its normal timekeeping. The term comes from the Greek words "chronos" (time) and "grapho" (to write). In modern usage, the terms are often used interchangeably, though chronograph typically refers to a wristwatch with stopwatch features.
How to use laps and splits
A stopwatch is most useful when it separates total elapsed time from the smaller segments inside it. That is the difference between a split and a lap.
Split time
A split is the total time at a checkpoint. Runners, presenters, and operators use splits to see where they are against the whole task.
Lap time
A lap is the time since the previous checkpoint. It shows whether each repeated segment is getting faster, slower, or staying consistent.
Stopwatch uses and what to record
Different tasks need different timing notes.
| Use case | Record | Why |
|---|---|---|
| Workout or race | Lap and split | Shows each interval and the total pace. |
| Presentation rehearsal | Split at each section | Reveals which section is using too much time. |
| Support or operations task | Start, stop, and total elapsed time | Makes the handoff or incident timeline easier to audit. |
Practical examples
A stopwatch becomes more useful when the labels match the activity.
Rehearsing a talk
Press lap after the intro, each main section, and the close. The split shows total runtime; the lap shows section length.
Timing repeated work
For ten identical tasks, press lap after each one. The lap list shows whether the process is improving or fatiguing.
Recording an incident
Use one continuous stopwatch and copy the lap table at the end so the timeline has consistent elapsed times.
When manual timing is not enough
A stopwatch is excellent for practice, comparison, and informal measurement. Some timing jobs need stricter rules because the result may be contested or audited.
Human reaction time matters
Starting and stopping by hand adds uncertainty. For close race results or fine performance comparisons, reaction time can be larger than the difference being measured.
Records need repeatable rules
If the result will be published, challenged, or compared over time, define when timing starts, when it stops, and who is responsible for marking laps.
Official timing needs approved equipment
Races, records, compliance checks, experiments, and safety procedures should use the equipment and rules required by the organizer or standard.
Reference notes
These references explain formal timekeeping language and examples of official timing rules.