Tree volumes are typically not measured directly. Some inventories just measure the diameter in 1.3m height, measure or estimate the tree height and use a form factor to estimate stem volume. Those form factors are based on relations between diameter (and height, crown length, . . . ) and estimated tree volumes. Those tree volumes typical are estimated by using section wise measured stem diameters. Some methods to estimate tree volume using section wise diameters are compared. From this investigation the methods interpolating between the measured diameters and building the integral of those areas along the stem could be recommended. From the interpolation methods the one which are monotonic and non overshooting showed good results. Of the interpolation methods compared, the method developed by Steffen in 1990 showed the best performance.
