A good rule of thumb to follow: Cook for 6 minutes per pound of chicken once under pressure. So, a 4-pound chicken cooks for 24 minutes, a 5-pound chicken cooks for 30 minutes, and so on. However, don’t forget to take the other steps into account. For instance, an Instant Pot takes about 10 minutes to pressurize. And you need an additional 15 minutes at the end for the pressure to release naturally. So if you are cooking a 5-pound chicken, total cook time will be 55 minutes (excluding about 5 minutes to broil the chicken at the end). With broiling, it will be closer to an hour of total cook time.