How Does a Stopwatch Work?

Stopwatches are watches that time events. Instead of telling one the time of day, the stopwatch tells the person how long it took to perform a certain function. Some stopwatches can time multiple events. Some stopwatches can time parts of the event along with the total time of the event.


The stopwatch contains buttons to perform certain functions, such as starting, stopping and split timing. Your stopwatch could have other functions such as an alarm or calendar function. Refer to your owner’s manual for a list of all functions of your stopwatch.


The stopwatch works by pressing the start button when the event begins. For example, if you were timing a race, you would press the start button when the race starts. When the race is over, press the stop button. The time of the race displays on the stopwatch just as the time of day would display on your wristwatch. Clear the watch when you are done so that is is ready for the next event you want to time. Most stopwatches do not attach to a person’s wrist--the person wears it around his neck or carries it in his pocket.


Stop watches have a split button to time parts of the event. For example, if your race is a relay race and you want to know the time for each relay, press start at the start of the race. At the same time, press the split button on your stopwatch. Now when the first relay is done, press split. The watch displays the time for the first relay but continues to accrue time for the total race. Press the split again for the next relay. Repeat this until the race is over, and then press stop.

The watch will display the total time for the race. Press split to get the time for the first relay. Press split again for the second time and continue until you have all of the relay times. Stopwatches will only hold a certain amount of split times, so check your owner’s manual to see how many split times your watch holds.


Stopwatches have a timer built into them. A timer is the reverse of a stopwatch. Instead of timing the event, the timer times how long it takes you to do something. For example, if you leave your home to go to work, press start on the timer mode. When you reach work, press stop on the timer mode. The time it takes you to get to work displays on the face of the stopwatch.