You should switch positions about every 2 minutes, or sooner if the person doing compressions is getting tired or their compressions are getting shallow.

Key guideline

  • Most CPR training and guideline summaries recommend switching rescuers roughly every 2 minutes , which is about 5 cycles of 30 compressions and 2 breaths in adult CPR.
  • The switch should be done during a natural brief pause, such as:
    • A rhythm or pulse check
    • AED analysis or shock delivery
    • The end of a 30-compression set, before the next breaths start

Watch for fatigue

Even if 2 minutes have not passed, switch immediately if:

  • The rescuer doing compressions is clearly tiring
  • Compression depth or rate is dropping, or the recoil is incomplete
  • Their arms are bending, they’re pausing more, or they can’t stay on the beat

Switching early keeps compressions hard, fast, and effective, which matters more than sticking rigidly to the clock.

TL;DR: In two-person CPR, plan to switch about every 2 minutes (around 5 cycles of 30:2) during a natural pause, and switch sooner any time compression quality drops due to fatigue.

Information gathered from public forums or data available on the internet and portrayed here.