Embodiments described herein are directed to a method to determine a speed profile for a stairlift, wherein the stairlift includes a guide device, a carriage, and user interaction device. The carriage is rotatable around a vertical axle by a first drive. A specific mass moment of inertia for a specific person is determined by measuring a correlation between applied torque and resulting rotational acceleration for the first drive or the specific mass moment of inertia for a specific person is determined by measuring the specific persons weight while the specific person is carried on the carriage. An optimal torque is set according to the specific mass moment of inertia. The speed profile is determined applying at the most the optimal torque with the first drive.