During adult CPR, what is the recommended chest compression depth and rate?

• A. 5-6 cm depth at 100-120/min
• B. 2-3 cm depth at 60-80/min
• C. 6-7 cm depth at 80-100/min
• D. 1-2 cm depth at 40-60/min

Answer: (B)

The key idea is delivering chest compressions that move enough blood to sustain circulation during cardiac arrest. For adults, that means pushing hard to a depth of about 5 to 6 centimeters (roughly 2 inches) and doing so at a rate of about 100 to 120 compressions per minute. This depth is deep enough to generate meaningful blood flow, while the rhythm around 100–120 per minute keeps a steady pace similar to a heart trying to pump, without sacrificing the chest’s ability to recoil fully between compressions. Full recoil is essential to allow the heart to fill again between compressions.

If you go shallower, like 2 to 3 centimeters, the pressure generated is insufficient to maintain cerebral and coronary perfusion. A slower rate, such as 60 to 80 per minute, reduces the volume of blood moved each minute and lowers overall perfusion. Conversely, compressions that are too deep or too fast can impede recoil and reduce effectiveness. So the recommended balance—5 to 6 cm depth and 100 to 120 per minute—best supports blood flow until rescuers can provide advanced care or a defibrillator takes over.