What rpm does a helicopter have to have to take lift?

The RPM required for a helicopter to generate lift varies based on factors such as the helicopter's design, weight, and rotor size. Typically, rotor RPMs range from about 300 to 500 RPM for most helicopters during normal flight conditions. However, the specific RPM needed to achieve lift will depend on the helicopter's rotor characteristics and the atmospheric conditions. It's essential for pilots to monitor RPM to ensure optimal performance and safety during flight.