Chest compressions are performed on the lower half of the sternum, the flat bone that runs down the center of your chest. This applies to adults, children, and infants, though the technique for each age group differs. Getting the location right matters because pressing in the correct spot creates the most effective blood flow to the brain and heart during cardiac arrest.
Hand Placement for Adults
For an adult, you compress the lower half of the breastbone. To find the spot, locate the bottom edge of the breastbone where it meets the soft tissue of the upper abdomen. Place the heel of one hand just above that point, then stack your other hand directly on top. Lace your fingers together and lift them so they don’t press against the ribs. Only the heel of your bottom hand should contact the chest.
This placement matters because the heart sits just behind and slightly to the left of the sternum. Pressing on the lower half of this bone compresses the heart between the breastbone and the spine, which manually pumps blood out to the body. Compressions in other locations are less effective at generating blood flow and more likely to cause injury to surrounding structures.
How Deep and How Fast to Push
For adults, push the chest down at least 5 centimeters (about 2 inches) but no deeper than 6 centimeters. Studies of over 13,700 patients found the best survival rates when compressions were delivered at 100 to 119 pushes per minute. That rhythm is roughly the tempo of the song “Stayin’ Alive,” which is a commonly used mental metronome.
Between each compression, let the chest come all the way back up to its resting position. This full recoil creates a brief vacuum inside the chest cavity that draws blood back into the heart, refilling it for the next squeeze. Even leaning slightly on the chest between compressions reduces venous return and lowers the amount of blood each compression sends out. Lift your weight completely between pushes.
Positioning Your Body
Kneel beside the person so your shoulders are directly over their chest. Lock your elbows straight and keep your arms perpendicular to the person’s body at a 90-degree angle. This alignment lets you use your upper body weight to drive each compression rather than relying on arm strength alone. If your arms are angled, you’ll fatigue faster and your compressions will become shallower within minutes.
A firm surface underneath the person helps, though research shows the difference between a firm mattress and the floor is smaller than you might expect. A 2024 meta-analysis found that moving someone to the floor added only about 5 millimeters of compression depth compared to a firm hospital mattress. If someone collapses on a bed, don’t waste time moving them to the floor. Start compressions immediately.
Compression Location for Children and Infants
For children (roughly age one through puberty), the compression location is the same as adults: the lower half of the breastbone. Use one or two hands depending on the child’s size, and compress the chest about 2 inches deep, or roughly one-third of the chest’s front-to-back diameter.
For infants under one year old, compress the center of the chest using two fingers placed just below the nipple line. Push down about 1.5 inches (roughly 4 centimeters). The ratio stays the same as adults when a single rescuer is present: 30 compressions followed by 2 breaths, repeated in cycles until help arrives or the infant starts breathing.
Pregnant Women: Same Spot
Older CPR guidelines from 2010 suggested placing your hands higher on the breastbone for women in late pregnancy, based on the assumption that the enlarged uterus pushes the heart upward. That recommendation has since been removed. MRI studies showed no significant vertical displacement of the heart during pregnancy, and current guidelines call for the standard hand position on the lower half of the sternum regardless of pregnancy status.
Why Correct Placement Reduces Injury
Rib fractures are a known consequence of chest compressions, and they’re more common than most people realize. Among cardiac arrest patients who received a chest CT afterward, about 50% had at least one rib fracture. Broader estimates suggest chest wall injuries occur in 66% to 95% of patients who receive CPR, with isolated rib fractures being the most frequent at 66% to 83% of cases. Sternal fractures occur in 8% to 30%.
Proper hand placement doesn’t eliminate this risk, but it reduces it. When your hands drift off the center of the breastbone and onto the ribs, the force concentrates on thinner, more fragile bones. Keeping the heel of your hand squarely on the lower sternum distributes the compression force through the strongest part of the chest wall. Rib fractures during CPR are not a sign of failure. They’re a known tradeoff for generating enough force to keep blood circulating in someone whose heart has stopped.