When performing one-rescuer cardiopulmonary resuscitation (CPR) on a child, the correct ratio to deliver is 30 chest compressions at a depth of 1.5-2 inches and a rate of 100-120 beats per minute followed by 2 rescue breaths with the head tilted, chin lifted, and nostril pinched closed. This ratio of 30:2 is the same as with adults in need of high-quality CPR.
The ratio decreases, however, with two rescuers to 15:2 with a cycle every two minutes in order to avoid upper extremity fatigue from chest compressions.