Which Chest Compression Techniques Can Be Used for a Small Child: Depth, Rate and Hand Placement by Age

For a small child, use one or two hands on the lower half of the breastbone, compress at least one-third of the chest's front-to-back depth (about 5 cm or 2 inches), and push hard and fast at 100–120 compressions per minute. Children past puberty get adult technique with two hands. Infants under 12 months get the two-finger technique or the two-thumb encircling technique. Rescuer count decides which infant method you use: two thumbs for two trained rescuers, two fingers for one.

This is general educational information, not a diagnosis or treatment plan. Any child who is unresponsive and not breathing normally needs emergency services called immediately — in the US and Canada dial 911, in the UK and Europe 112, in Australia 000.

What Counts as a "Small Child" for Compression Purposes

Resuscitation councils split young victims by puberty, not by height, weight, or shoe size. The American Heart Association's 2020 guidelines treat victims up to the start of puberty as children for CPR purposes, and the European Resuscitation Council's 2021 guidelines use the same puberty marker. A 9-year-old who has started puberty gets adult compressions, while a sturdy 11-year-old who hasn't gets child compressions.

The reason is mechanical. Before puberty, the chest wall is compliant and the heart sits higher relative to the sternum, so a compression depth scaled to the ribcage works better than the adult standard of 5–6 cm. After puberty, the ribcage stiffens toward adult geometry and the adult depth range applies. Age in years is a rough proxy only — the guideline language is deliberate about that.

Here is how the three age bands differ across the measurements that matter:

A newborn in the delivery room is a separate protocol entirely — the neonatal algorithm — and isn't covered by the infant band above. If you're unsure whether a child has reached puberty, the AHA's guidance is to treat them as a child rather than defaulting to adult technique.

One-Hand Versus Two-Hand Compressions: Choosing by Chest Size

Chest size, not the child's age, settles the hand question. The AHA's 2020 guidelines state that rescuers should use one or two hands for child compressions according to what the rescuer needs to achieve the required depth. If one hand gets you to roughly 5 cm with good recoil, one hand is fine. If the chest feels stiff or you're tiring fast, stack the second hand.

The two-hand technique is the familiar adult stack: heel of one hand on the lower half of the sternum, the second hand on top, fingers interlocked or lifted so only the heel contacts the ribs. The one-hand technique uses a single heel in the same spot, with the other hand free to hold the child's head or steady your position. Neither is wrong; the depth target is the referee.

Press hard enough that the chest visibly compresses. A Cochrane review published in 2019 by Hodges and colleagues looked at real-time feedback devices and found they improve compression depth and rate during training and actual resuscitation, which tells you how easily humans under-compress without a prompt. That's the failure to guard against with a small chest: the fear of pressing too hard makes rescuers too shallow.

Leaning matters more than most people realize. If you keep weight on the chest between compressions, the heart can't refill and output drops. Let the chest come all the way back up, keep your hand in contact with the skin, and don't bounce.

The Two-Finger Technique for Infants and When It Fails

The two-finger technique is the one-rescuer infant standard: index and middle fingers of one hand, tips on the lower half of the sternum just below the nipple line, compressing about 4 cm. It's teachable in seconds, which is why it anchors most lay-rescuer courses. It's also the weaker of the two infant methods in the research.

The two-thumb encircling technique uses both thumbs side by side on the lower sternum while the hands wrap around the infant's chest and the fingers support the back. A 2019 systematic review and meta-analysis in Resuscitation by Kim and colleagues pooled trial data and found two-thumb encircling produced higher compression depth and better blood pressure than two fingers. The trade-off is practical: with one rescuer, encircling hands make it hard to manage the airway and deliver breaths.

So the split rule is rescuer count. Alone with an infant, use two fingers, call for help on speakerphone, and switch to two thumbs the moment a second trained person arrives. With two rescuers, the second person takes the airway and the compressor uses two thumbs. The 15:2 ratio for two-rescuer infant CPR fits that arrangement.

Two thumb placement errors show up repeatedly in skills testing. Placing the thumbs too low drives the xiphoid process into the liver; placing them too high does nothing useful. Use the nipple line as the landmark and stay just below it, on the center of the chest.

Compression Rate: The 100–120 Per Minute Window Applies to Every Child

The rate target doesn't change with age. Every pediatric and adult guideline since 2010 has set 100–120 compressions per minute, and that figure survives into the AHA's 2020 update and the ERC's 2021 update. Too slow and cardiac output falls; too fast and depth shrinks because rescuers trade push for speed.

You don't need a metronome. The AHA's training materials use the Bee Gees' "Stayin' Alive," which runs at about 103 beats per minute, as a pacing reference, and many instructors use "Nellie the Elephant" for the same reason. Hum it and push on the beat. If you have a smartphone metronome app, 110 is a safe setting that sits inside the window.

The failure case worth knowing is the speed-depth trade-off. Rescuers who push above 120 per minute consistently lose depth, and shallow compressions are the single most common quality defect in real resuscitation. If you had to choose, err toward slightly slower and deep enough. The guideline window is narrow for a reason, but the chest moving 5 cm beats a blur of movement that moves it 2 cm.

Interruptions cost more than most people expect. Each time you stop for a breath, a pulse check, or a repositioning, blood pressure falls toward zero and needs several compressions to rebuild. The AHA's guidance is to keep pauses under 10 seconds, and that target applies to children exactly as it does to adults.

Hand Placement on the Lower Sternum and the Mistakes That Cost Depth

Place the heel of your hand on the lower half of the breastbone, in the center of the chest, in line with the nipples. That single sentence covers every age band from infant to adult — only the hand count and depth change. The AHA's 2020 guidelines use the same landmark language for children as for adults.

The xiphoid process at the bottom tip of the sternum is the danger zone. Compressions there can fracture it and drive it into the liver, and they generate poor cardiac output because you're below the heart. Equally, hands placed too high on the upper sternum compress the chest without squeezing the ventricles, which is why "center of the chest" is the phrase every course repeats.

A common lay-rescuer error is pressing off-center toward one side, where the ribs flex instead of the sternum moving. Watch your knuckles: if they're drifting toward a nipple, you've slid off the midline. Reposition without lifting your hand fully off the skin and resume immediately.

Shoulders over hands saves your arms and improves depth. Lock your elbows, hinge from the hips, and keep your back roughly vertical over the child. Rescuers who push from bent elbows fatigue within a minute or two, and fatigue shows up as progressively shallower compressions long before the rescuer notices. If a second trained rescuer is present, swap every two minutes or roughly every five cycles of 30:2 — the swap takes seconds and protects depth.

One Rescuer Versus Two: How the Ratio Changes the Technique

The 30:2 ratio governs a lone rescuer for any child or infant. Push 30 times, give two rescue breaths, repeat. The 15:2 ratio applies once a second trained rescuer joins and takes the airway for a child or infant. The AHA's 2020 guidelines and the ERC's 2021 guidelines both endorse this split for trained two-rescuer teams.

Here's the sequence a lone rescuer runs, in performance order:

1: Check responsiveness and breathing for no more than 10 seconds. Gasping is not normal breathing — treat it as cardiac arrest. 2: Shout for help, put your phone on speaker, and call emergency services. If someone else is nearby, send them for an AED. 3: If the child isn't breathing normally, start compressions immediately. Position: lower half of the sternum, one or two hands depending on chest size. 4: Push at 100–120 per minute to about one-third of chest depth, about 5 cm, allowing full recoil. 5: After 30 compressions, give two rescue breaths if you're trained and willing. Each breath goes in over about one second, just enough to see the chest rise. 6: Resume compressions immediately. Don't pause to recheck. 7: Swap compressor roles every two minutes if help is available. Use the AED as soon as it arrives and follow its prompts.

For an infant, substitute steps 3 and 5 with two-finger compressions at about 4 cm and two small puffs — enough to make the chest visibly rise, not a full adult breath. In two-rescuer infant CPR, switch to two-thumb encircling and the 15:2 ratio.

Failure handling matters here. If a breath doesn't go in, reposition the head — a child's airway is easily blocked by chin-to-chest positioning — and try again. If it still won't go in, return to compressions. Don't burn time hunting for the cause. If you're unwilling or untrained to give breaths, do compression-only CPR and keep going; the AHA's 2020 guidelines support compression-only CPR for untrained bystanders, and some circulation beats none.

Depth Targets in Centimeters and Inches, and How to Judge One-Third

The pediatric compression depth rule is a fraction, not a fixed number: at least one-third of the chest's front-to-back (anteroposterior) diameter. In practice that translates to about 4 cm, or 1.5 inches, for infants and about 5 cm, or 2 inches, for children. The AHA's 2020 guidelines state the child figure as at least one-third of AP diameter, approximately 2 inches.

Why a fraction rather than a number? Because a 14 kg 4-year-old and a 30 kg 9-year-old have different chests, and one-third scales to the child in front of you. If you can't estimate depth in centimeters in the moment — and most people can't — use the visual rule: the chest should compress visibly, about a third of the way down. If you're pressing and the chest isn't moving, you're too shallow.

The 2015 AHA guidelines update, published in Circulation, reviewed pediatric compression depth evidence and noted that rescuers frequently under-compress children because they fear causing injury. Rib fractures from CPR do happen, particularly in older children, but a fractured rib is survivable and an uncompressed heart is not. The guideline position is clear: push to the depth target.

What determines whether you hit it: chest compliance, your positioning, your fatigue, and whether you're using one hand when you need two. Nothing else. A 6-year-old with a stiff chest and a rescuer using one hand will under-compress; two hands fixes it. A tired rescuer at the three-minute mark will under-compress regardless of technique, which is why the two-minute swap exists.

Where the Guidelines Come From and How Often They Change

The two bodies that set the numbers are the American Heart Association, through its Circulation guidelines, and the European Resuscitation Council, through its Resuscitation guidelines. The AHA's current CPR and emergency cardiovascular care guidelines were published in 2020, and the ERC's in 2021. Both draw on the International Liaison Committee on Resuscitation's consensus on science, which reviews the evidence and issues treatment recommendations that the regional councils then adapt.

The cycle runs roughly every five years, with focused updates between them. That matters if you're relying on a course you took years ago. The 100–120 rate and the 5 cm child depth have been stable across the 2015, 2020, and 2021 documents, but the recommendation on compression-only CPR for untrained bystanders, the emphasis on real-time feedback, and the two-thumb preference for two-rescuer infant CPR have all firmed up over that period.

One thing the guidelines are specific about that lay summaries often drop: the child category starts at 1 year and runs to puberty, and infants under 1 year are a separate algorithm. An 11-month-old and a 13-month-old are treated differently because the infant chest is smaller and the two-finger or two-thumb technique is what fits it. Get the band right before you worry about anything else.

Training is the difference between knowing these numbers and executing them under stress. The AHA and ERC both recommend hands-on courses with manikin practice and skills testing, and no article substitutes for that. A 2021 Resuscitation review of bystander CPR training found that hands-on practice with feedback produces better compression quality at follow-up than video or self-directed learning alone.

If you take one thing from all of this, take the two-minute swap and the depth-versus-speed trade. Those two behaviors account for most of the gap between textbook CPR and real CPR.

This article is general educational information, not a diagnosis, treatment plan, or substitute for certified training. Compression depth and technique for a specific child should follow the current guidelines from the American Heart Association or European Resuscitation Council and instruction from a qualified local CPR instructor. If a child is unresponsive and not breathing normally, call your local emergency number immediately — 911 in the US and Canada, 112 in the UK and Europe, 000 in Australia — and follow the dispatcher's instructions.

FAQ

Can I use two hands on a 2-year-old?

Yes, if one hand can't reach the depth target. The AHA's 2020 guidelines allow one or two hands for child compressions based on what the rescuer needs to achieve about one-third of chest depth, roughly 5 cm or 2 inches. Most rescuers find two hands easier on a toddler's stiff chest. The technique is identical to adult CPR — heel of one hand on the lower sternum, second hand stacked on top.

Is 5 cm too deep for a small child's chest?

No — 5 cm is the guideline target for children from 1 year to puberty, not a ceiling. The AHA sets child depth at approximately 2 inches or one-third of AP diameter, and the evidence review behind the 2015 update found under-compression is far more common than over-compression. Injury risk exists but is outweighed by the cost of shallow compressions.

Do I give rescue breaths to a child if I'm alone and untrained?

Compression-only CPR is acceptable for untrained bystanders under the AHA's 2020 guidelines. Push hard and fast at 100–120 per minute without pausing for breaths, and keep going until help or an AED arrives. If you're trained and willing, add two breaths after every 30 compressions. Untrained rescuers who attempt breaths often hyperinflate a small chest.

What's the difference between infant and child CPR technique?

Infants under 12 months get two-finger compressions (or two-thumb encircling with two rescuers) at about 4 cm, or 1.5 inches; children from 1 year to puberty get one or two hands at about 5 cm. The rate, 100–120 per minute, is the same for both. Newborns in the delivery room follow a separate neonatal protocol.

How fast do compressions need to be for a 4-year-old?

100 to 120 compressions per minute — the same window as for adults and infants. At 110 per minute you complete 30 compressions in roughly 16 seconds, so a full 30:2 cycle takes about 20 seconds including the two breaths. If you drift above 120, depth usually drops, so slow down rather than speed up.

Should I stop compressions to check for a pulse?

No. For a lay rescuer, the AHA's guidance is not to interrupt compressions for pulse checks; signs of life are unreliable and pauses cost blood pressure. Continue until the child moves, breathes normally, or trained responders take over. Each interruption should stay under 10 seconds if it happens at all.

Does an AED work on a small child?

Yes. Use a pediatric AED pad set and pediatric attenuator if available; if not, use adult pads placed so they don't touch each other. The AHA's 2020 guidelines support AED use in children, and the device's voice prompts tell you which mode it's in. Don't delay defibrillation to hunt for pediatric pads.

What if I can't get the chest to rise when I give breaths?

Reposition the head first — a child's airway is easily blocked by chin-to-chest positioning — then try one more breath. If it still won't go in, resume compressions immediately rather than searching for a cause. The AHA's guidance is to return to compressions and not let airway troubleshooting eat the pause.