Comprehensive comparison between theory and experiment has been made on the characteristics of a high‐Tcdc superconducting quantum interference device (SQUID). Using the theoretical expressions for the SQUID characteristics, we can quantitatively predict the transfer functionV&fgr;and the magnetic‐flux noiseS&Fgr;from SQUID parameters without any adjustable parameter. It is shown that the theoretical predictions agree well with the experimental results for a wide range of SQUID parameters. This agreement shows the usefulness of the present theory in the design of the high‐TcSQUID. Exceptional deviations between theory and experiment are the absolute values, i.e., the factor of 0.6 difference inV&fgr;and the factor of 10 difference inS&Fgr;. Possible reasons for these discrepancies are discussed. ©1995 American Institute of Physics.