During CPR, chest compression fraction should be at least what percentage?

The answer

Chest compression fraction should be at least 60%, and rescuers should aim for 80% or more. CCF is the percentage of total CPR time during which chest compressions are actually being delivered. If you spend 8 out of every 10 minutes of an arrest actively compressing, your CCF is 80%. Guidelines set 60% as the minimum acceptable performance and treat 80% as the high-quality target because more compression time means more blood flow to the heart and brain.

The way to raise CCF is simple to state and hard to do: minimize interruptions. Every pause — for rhythm checks, for defibrillator charging, for switching rescuers, for placing an airway — is time the heart and brain receive no circulation. The higher your CCF, the closer the patient comes to receiving continuous perfusion, which is strongly associated with better survival and neurological outcomes.

How CCF is calculated

CCF is a ratio: compression time divided by total resuscitation time, expressed as a percentage. If a resuscitation lasts 10 minutes and compressions are delivered for 7 of those minutes, CCF is 7 ÷ 10 = 70%. Pauses accumulate quickly. A 10-second pause for a pulse check, repeated every 2 minutes over a long code, can pull a CCF from the ideal 80% zone down toward the 60% floor.

This is why teams practice choreographed handoffs, pre-charging the defibrillator before a rhythm check, and limiting pulse checks to 10 seconds or less. Each of those techniques exists specifically to protect the compression fraction.

Why the exact numbers matter

Students sometimes see conflicting figures online — some sources cite only 60%, others emphasize 80%. Both are correct pieces of the same guideline: 60% is the minimum threshold; 80% is the aspirational target for high-performance CPR. Choosing "at least 60%" is the safest answer to the literal question "should be at least," because that is the floor. But a well-run resuscitation aims well above it.

Contrast CCF with the other well-known CPR metrics so you do not confuse them. The rate of compressions should be 100–120 per minute, and the depth for an adult should be at least 2 inches (5 cm) but no more than 2.4 inches (6 cm). These describe how each compression is delivered, whereas CCF describes how much of the whole event is spent compressing at all. A rescuer can have perfect rate and depth yet a poor CCF if they pause too often — which is exactly why the fraction is tracked separately.

The practical bottom line: push hard, push fast, and above all keep pushing. Anything that keeps hands on the chest and interruptions under about 10 seconds is protecting the compression fraction and, with it, the patient's chance of survival.