Abstract: Method and device for counting clock pulses for the purpose of determining period length works in accordance with an absolute time measuring principle, provides at least a single main counter which runs uninterruptedly from the start of measurement to the end of measurement and a channel counter for each of a number n of measuring channels. By stopping a channel counter at the associated measurement period end and reading out the counter reading thereof as well as that of a supplementary upper main counter part which contains the higher-order count positions, a determination is made of the total time elapsed from the start of measurement up to the respective detected period end, and thereafter the target period lengths are determined by forming the difference of successive count values. The invention can be used, for example, for the high-precision measurement of the speed of a system rotating about an axis.