Abstract: In the design of laser interference absolute gravimeters, the falling-body for each measurement needs to freely fall about 7-20 cm along the vertical direction, corresponding to a gradient error up to 60 μGal. So the measurement-height must be computed where the combined effect of the gravity gradient is equal to zero. This paper bases on the analysis for the equation of the falling-body movement and proposes a new algorithm to calculate the measurement-height of the absolute gravimeter. From the comparison with other algorithms we could find:(1) if the beginning time of the trajectory is close to zero(less than 0.015 s), the measurement height of the absolute gravimeters using our algorithm coincides to the other algorithms, with the maximum deviation less than 3 mm and the gradient error less than 1 μGal; (2) during the process of independent research and development, if the beginning time of the trajectory is more than zero(0.015 s or even longer), the measurement height calculated by our algorithm is more reasonable.