how deep should you push on the chest of an adult when you do hands-only cpr?

When performing hands-only CPR on an adult, you should push straight down on the chest at least 2 inches (5 centimeters) but no more than 2.4 inches (6 centimeters). Use your entire body weight, not just your arms, to compress the chest. The compressions should be delivered hard and fast, at a rate of 100 to 120 compressions per minute, allowing the chest to fully recoil between compressions