Beta is computed self‐consistently in reversed field pinches, using reduced magnetohydrodynamics with transport. Qualitative agreement with the OHTE experiment [Bull. Am. Phys. Soc.29, 330 (1984)] is found. A derivation of the finite beta reduced equations is presented. The relation of the dynamo effect to anomalous transport is described. The scaling of the &dgr;B/BwithSis obtained.