Home › Time & Date › 15 Second Timer
15 Second Timer
A fifteen-second countdown, ready the moment the page loads: press Start (or Space) and an alarm sounds after 15 seconds, with 3-2-1 beeps at the end. Handy for pulse checks, game turns and short holds.
Last updated:
0:15
Ready
Presets
Shortcuts: Space start / pause · R reset · F fullscreen. Add ?s=40 to the address to open a custom number of seconds.
Advertisement
Advertisement
How to use the 15 Second Timer
- Press Start or hit the Space bar. The 0:15 countdown begins immediately.
- Leave the 3-2-1 beeps on to hear when the last seconds are ticking away.
- Fine-tune the length with the ± buttons or pick another preset.
- Choose an alarm sound and volume, then press Play test sound to check you can hear it.
- When time is up, press Stop alarm or Space. Press R to reset to 0:15.
How long is 15 second?
| Measure | 15 Second equals |
|---|---|
| Seconds | 15 s |
| Milliseconds | 15,000 ms |
| Hours | 0.004167 h |
| Share of a day | 0.0174% (1/5760 of a day) |
| Walking at 5 km/h (3.1 mph) | about 0.021 km (0.013 mi) |
| Speaking at 130 words per minute | about 32 words |
| Reading at 230 words per minute | about 58 words |
What you can do in 15 second
| Activity | Why 15 second works |
|---|---|
| Plank and hold drills | Short holds for beginners and warm-ups |
| Turn timer | Fair, quick turns in board and party games |
| Speed rounds | Fast answers in classroom quizzes |
| Stretching | A short hold for each dynamic stretch |
| Pulse check | Count your pulse for 15 seconds and multiply by 4 to get beats per minute |
| Cooking | Short stirring or toasting bursts |
How the countdown keeps exact time
When you press Start, the timer records the end moment as start time + 15,000 ms on the browser's monotonic clock (performance.now()). Every screen update subtracts the current time from that end moment instead of counting ticks, so a throttled background tab or a busy computer cannot make it fall behind. Pausing stores the time left, and Resume sets a new end moment that far in the future.
Frequently asked questions
How do I set a 15 second timer?
It is already set. Press Start or the Space bar and the countdown runs from 0:15 to zero, then the alarm rings until you stop it.
How many milliseconds are in 15 seconds?
15 seconds is 15,000 milliseconds, or 0.25 of a minute.
How do I measure my heart rate with a 15 second timer?
Find your pulse on your wrist or neck, start the timer and count the beats until it rings. Multiply the count by 4 to get your heart rate in beats per minute.
Can I restart it quickly?
Yes. Press R to reset to 0:15 and Space to start again, so you can run round after round.
Can I change the length?
Use the ±5 s buttons, choose a preset, or add ?s= with a number of seconds to the address, for example ?s=20.
Is it accurate?
Yes. The timer stores the exact end time and measures the time left from the clock, so it does not drift even if the browser is busy.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.
Related tools
10 Second TimerA ready-to-go 10 second countdown with alarm, presets and fullscreen view.20 Second TimerA ready-to-go 20 second countdown with alarm, presets and fullscreen view.Countdown TimerOnline timer with alarm sound.StopwatchOnline stopwatch with laps, fullscreen mode and CSV export.Online Alarm ClockSet multiple alarms with sounds, snooze and keep-screen-awake.10 Minute TimerA ready-to-go 10 minute countdown with alarm and fullscreen.30 Minute TimerA ready-to-start 30 minute countdown with alarm, fullscreen and presets.5 Minute TimerA 5-minute countdown with alarm sound and fullscreen mode.1 Minute TimerA ready-to-go 60 second countdown with alarm and fullscreen.15 Minute TimerA ready-to-go 15 minute countdown with alarm, presets and fullscreen view.20 Minute TimerA ready-to-go 20 minute countdown with alarm, presets and fullscreen view.Pomodoro Timer25/5 focus and break timer with alerts and a task list.Interval TimerHIIT and Tabata interval timer with rounds, sets, beeps and voice cues.Chess ClockTwo-player chess timer with blitz presets, increment and delay modes.Days Until CalculatorCount down the days to any event.Classroom TimerBig visual countdown ring timer for classrooms with presets and end sounds.Christmas CountdownLive countdown of days, hours, minutes and sleeps until Christmas Day.New Year CountdownLive countdown to New Year in your time zone, with year progress and fireworks.Meditation TimerCalm meditation timer with singing bowl bells, interval chimes, ambient sounds and breathing guide.30 Second TimerA ready-to-go 30 second countdown with alarm, presets and fullscreen view.2 Minute TimerA ready-to-go 2 minute countdown with alarm, presets and fullscreen view.3 Minute TimerA ready-to-go 3 minute countdown with alarm, presets and fullscreen view.45 Minute TimerA ready-to-go 45 minute countdown with alarm, presets and fullscreen view.1 Hour TimerA ready-to-go 1 hour countdown with alarm, presets and fullscreen view.2 Hour TimerA ready-to-go 2 hour countdown with alarm, presets and fullscreen view.Halloween CountdownLive countdown to Halloween in days, hours, minutes and seconds.Thanksgiving CountdownLive countdown to Thanksgiving in days, hours, minutes and seconds.Valentine's Day CountdownLive countdown to Valentine's Day in days, hours, minutes and seconds.Easter CountdownLive countdown to Easter in days, hours, minutes and seconds.4 Minute TimerA ready-to-go 4 minute countdown with alarm, presets and fullscreen view.7 Minute TimerA ready-to-go 7 minute countdown with alarm, presets and fullscreen view.8 Minute TimerA ready-to-go 8 minute countdown with alarm, presets and fullscreen view.12 Minute TimerA ready-to-go 12 minute countdown with alarm, presets and fullscreen view.25 Minute TimerA ready-to-go 25 minute countdown with alarm, presets and fullscreen view.40 Minute TimerA ready-to-go 40 minute countdown with alarm, presets and fullscreen view.50 Minute TimerA ready-to-go 50 minute countdown with alarm, presets and fullscreen view.90 Minute TimerA ready-to-go 90 minute countdown with alarm, presets and fullscreen view.3 Hour TimerA ready-to-go 3 hour countdown with alarm, presets and fullscreen view.Multiple CountdownsTrack several event countdowns on one dashboard with emojis, progress bars and a share link.Presentation TimerSplit your talk time across slides and see time per slide, remaining time and if you're ahead or behind.Run Walk Interval TimerBeginner 5K run/walk interval timer with 9-week plan, voice cues, warm-up, cool-down and progress.Speech TimerGreen, yellow and red timing lights for speeches and Table Topics, with presets, fullscreen and a log.20-20-20 Eye Break TimerEvery 20 minutes, look 20 feet away for 20 seconds: reminders, notifications and a break overlay.Kegel Exercise TimerGuided squeeze and relax timer for pelvic floor exercises with levels, sets, sound, vibration and streaks.Coffee Brew TimerStep-by-step brew timer for pour-over, Chemex, French press and AeroPress with water targets.Succession Planting CalculatorSowing interval and dated plantings for a continuous harvest, up to your first fall frost.Tea Steeping TimerTea timer with green, black, oolong, white and herbal presets, water temperature and re-steeps.24 Hour TimerA ready-to-go 24 hour countdown with alarm, presets and fullscreen view.Mother's Day CountdownLive countdown to Mother's Day in days, hours, minutes and seconds.Father's Day CountdownLive countdown to Father's Day in days, hours, minutes and seconds.Fourth of July CountdownLive countdown to the Fourth of July in days, hours, minutes and seconds.Black Friday CountdownLive countdown to Black Friday in days, hours, minutes and seconds.Birthday CountdownEnter your birth date and see the days, hours, minutes and seconds until your next birthday.12 Hour TimerA ready-to-go 12 hour countdown with alarm, presets and fullscreen view.4 Hour TimerA ready-to-go 4 hour countdown with alarm, presets and fullscreen view.8 Hour TimerA ready-to-go 8 hour countdown with alarm, presets and fullscreen view.Chinese New Year CountdownLive countdown to Chinese New Year with the zodiac animal and dates for coming years.Diwali CountdownLive countdown to Diwali, the festival of lights, with dates for coming years.Eid al-Fitr CountdownLive countdown to the expected date of Eid al-Fitr, with estimates for coming years.Ramadan CountdownLive countdown to the expected start of Ramadan, with estimated dates for coming years.Wedding CountdownCount down to your wedding day; enter your date and share the link.Contraction TimerTime labor contractions with one tap: duration, frequency, hourly averages and a 5-1-1 check.Visual TimerShrinking red-disk visual countdown for kids and classrooms: drag to set 1–60 minutes.Breastfeeding TimerTime left and right side nursing, see which side to start next, feed intervals and night totals.Countdown Widget GeneratorDesign an embeddable countdown and copy HTML code or an iframe link for your website or Notion.Fasting TimerLive intermittent fasting timer with 16:8, 18:6, 20:4 and OMAD goals, stages and a fast log.Multiple Kitchen TimersRun several named cooking timers at once, each with its own alarm sound, presets and big display.AMRAP TimerAs-many-rounds-as-possible countdown with a 10 s lead-in, tap-to-count rounds, splits and a final score.