A steady chest-compression beat for CPR practice on a manikin. It clicks at 110 compressions per minute, counts each 30:2 cycle, pauses for two rescue breaths and speaks short prompts. This is a training aid: in a real emergency call your local emergency number (911 in the US) first.
Last updated:
Training aid only. In a real emergency call 911 (or your local emergency number) first and follow the dispatcher.
Ready
0
of 30 compressions
0:00Elapsed
0Cycles done
0Compressions
2:00Next switch
Mode
100110120
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How to use the CPR Metronome
Choose a mode: Adult 30:2, Child/infant 15:2 (two rescuers) or Hands-only for continuous compressions.
Keep the rate at 110 or set anything from 100 to 120 compressions per minute.
Press Start (or Space) and compress the training manikin on every click.
Give two breaths when the voice and the screen say so; compressions resume automatically when the pause ends.
Switch rescuers when the 2-minute alert sounds, then press Stop to see your practice summary.
CPR numbers at a glance
The figures below summarise the high-quality CPR targets in the 2020 American Heart Association guidelines (the European Resuscitation Council 2021 guidelines are very similar). They are for training reference only.
Adult and adolescent
Child (1 year to puberty)
Infant (under 1 year)
Compression rate
100-120 per minute
100-120 per minute
100-120 per minute
Compression depth
At least 2 in (5 cm), not more than 2.4 in (6 cm)
About 1/3 of chest depth, about 2 in (5 cm)
About 1/3 of chest depth, about 1.5 in (4 cm)
Hand position
Two hands, lower half of the breastbone
One or two hands, lower half of the breastbone
Two fingers or two-thumb technique, just below the nipple line
Ratio, 1 rescuer
30:2
30:2
30:2
Ratio, 2 rescuers
30:2
15:2
15:2
Pause for breaths
Under 10 seconds; each breath about 1 second with visible chest rise
How the timing works
At 110 compressions per minute one compression takes 60 / 110 = 0.545 seconds, so a set of 30 lasts about 16.4 seconds. Add a 5-second breath pause and one 30:2 cycle takes about 21.4 seconds, which means roughly five to six cycles fit into the two minutes between compressor switches. The chest compression fraction shown in the summary is the share of time spent compressing: (compressions × 60 / rate) ÷ elapsed time. With the default settings it works out to about 77%, close to the 80% that resuscitation teams aim for; shorter breath pauses push it higher.
Every click is scheduled on the Web Audio clock a fraction of a second in advance, so the tempo stays exact even if the page is busy or the screen redraws slowly.
Practice tips
Use a manikin or a firm cushion, never a person. Kneel beside it with your shoulders directly above your hands and arms straight.
Push on the click, release fully between clicks. Full chest recoil matters as much as depth.
Count out loud along with the beat; it helps you keep rhythm when the audio is hard to hear.
Practise the hand-over when the 2-minute alert sounds: the next rescuer is ready, swaps in during the breath pause and restarts within seconds.
Songs near the tempo such as many disco and pop tracks around 100-120 BPM are a popular memory aid, but a metronome is more precise.
Frequently asked questions
What is the correct CPR compression rate?
Current American Heart Association and European Resuscitation Council guidelines recommend 100 to 120 chest compressions per minute for adults, children and infants. This metronome defaults to 110 per minute, the middle of that range, so small drifts in your timing still stay within it.
Why 30 compressions and 2 breaths?
For adults the guideline ratio is 30 compressions followed by 2 rescue breaths, whether there are one or two rescuers. For children and infants a single rescuer also uses 30:2, while two trained rescuers use 15:2 because children more often need oxygen. The counter switches to 15 when you pick the child/infant two-rescuer mode.
How long should the pause for breaths be?
Guidelines aim to keep interruptions in compressions under 10 seconds. Each rescue breath is given over about 1 second, just enough to make the chest rise. The default 5-second pause leaves time to reposition the head and give both breaths; trained teams can shorten it.
How deep should compressions be?
For adults press at least 2 inches (5 cm) but not more than about 2.4 inches (6 cm). For children press about one third of the chest depth, around 2 inches (5 cm), and for infants about 1.5 inches (4 cm). Let the chest fully recoil between compressions and do not lean on it.
What is hands-only CPR?
Hands-only CPR means continuous chest compressions without rescue breaths. It is recommended for bystanders who are untrained or unwilling to give breaths when a teen or adult suddenly collapses. Choose Hands-only mode and the metronome will keep beating without pauses.
Why switch compressors every 2 minutes?
Compression quality drops as rescuers tire, often before they notice. Guidelines suggest switching the person doing compressions about every 2 minutes (roughly five cycles of 30:2), ideally in under 5 seconds. Turn on the 2-minute alert to practise the hand-over.
Can I use this instead of a CPR course?
No. This page is a practice metronome, not medical advice or certification. Take a hands-on course from an accredited provider such as the American Heart Association or the Red Cross, and in a real emergency call your emergency number first and follow the dispatcher's instructions.
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.