Abstract: The invention relates to a method for adapting the brake cylinder pressure (pc,actual; pc1/pc2/pc3/pc4) of a pneumatic brake of a rail vehicle (FZG). According to the invention, during a braking process, the momentary actual slip (sactual) between at least one wheel (2) of the rail vehicle (FZG) and a rail (3) is determined, a desired slip (sdesired) between the at least one wheel (2) and the rail (3) is predetermined, and the brake cylinder pressure (pc,actual; pc1, pc2/pc3, pc4), which corresponds to the difference of the actual slip (sactual) from the predetermined actual slip (sdesired), is modified such that the difference between the desired and actual slip is approximately zero or is at a minimum. The desired slip can be, selectively, in the micro or macro slip range. A braking state factor is determined in the event of a stable braking process, from axle speed measurements and brake cylinder pressures.