For adults, use a ratio of 30 compressions to 2 breaths.

Use a 15:2 ratio only when two rescuers are available for children.

Compress approximately one-third the chest depth, or about 2 inches (5 cm).

The two-thumb encircling hands technique is preferred for two-rescuer infant CPR.

Use one or two hands on the lower half of the sternum depending on child size.

Switch every 2 minutes to avoid fatigue and maintain high-quality compressions.

The rate should be 100–120 compressions per minute.

Use the head-tilt, chin-lift technique unless spinal injury is suspected.

Breaths should make the chest rise visibly.