Abstract: Discussed are certain problems related to calculation of the straightening force of the 2-2-2 type 6-roll tube straightener. As a result, a calculation methodology which is almost in the light of the actual straightening force status of the said straightener is established. With the Matlab software the straightening forces and the motor capacity are computed. Compared with the actual values of the straightener, the calculated values demon- strate that they are accurate enough to meet relevant engineering requirements, being worth applying as guide to calculation of actual capacity of the straightener.