21 Second Timer

1. Click “Start” to begin the 21-second countdown.
2. An alert will notify you when 21 seconds have elapsed.
3. Use the “Pause” button to temporarily halt the 21 second timer.
4. Click “Reset” to restart the timer at 21 seconds.
5. Adjust the duration using the dropdown menus for hours, minutes, and seconds.
6. Toggle sound alerts using the “Sound” button.
7. Enter fullscreen mode by clicking the “Fullscreen” button.

1. Fitness: Timing quick intervals or exercises.
2. Breathing exercises: Balanced breathing cycles.
3. Games: Short reaction windows.
4. Photography: Timing brief exposures.
5. Cooking: Timing quick tasks.

In just 21 seconds…

• An average typist can type around 105 keystrokes.
• Around 210,000 tweets are posted.
• Blood circulates through the heart about 4 times.

A 21-second timer is equivalent to:

• 0.005833 hours
• 0.350000 minutes
• 21,000 milliseconds

For a comprehensive time equivalent, including microseconds, nanoseconds, days, weeks, months, and years, please visit our Time Conversion Tool.