A new measurement concept for cut-to-length forest harvesters is presented in this paper. The cut-to-length method means that the trees are felled, delimbed and cut-to-length by the single-grip harvester before logs are transported to the roadside. The concept includes measurements done to standing trees before felling to calculate optimal length of logs. The modern forest harvesters use mechanical measurements for diameter and length. In this paper, we will discuss different non-contact methods of measuring a tree stem before felling and during the cut-to-length process. Standing tree stems are measured with a 3D scanner and a computer vision systems. Trunk processing is measured with a computer vision system. Based on these new measurements, tree cutting pattern could be optimized and harvester automation increased, resulting in higher resource utilization.