The paper introduces the CALIB 3.0 program, an updated version of the 14C age calibration program first released in 1986. The new version incorporates a large dataset of nearly 22,000 calibrated years (±18,400 14C years) and includes corrections to previously used data sets. The program is menu-driven and can be used to calibrate 14C ages, provide Δ14C series, and display results. It is compatible with IBM-compatible computers and can also be obtained for Macintosh upon request. The paper discusses the selection of calibration data and new features of the CALIB 3.0 program, including the handling of bidecadal and decadal data sets, marine samples, and atmospheric samples older than 10,100 (10,500) 14C years. The program allows for the calculation of calibrated ages, age ranges, and probability distributions, and includes options for error correction and statistical analysis. The paper also provides detailed information on the calibration curves and the graphical outputs available in the program.The paper introduces the CALIB 3.0 program, an updated version of the 14C age calibration program first released in 1986. The new version incorporates a large dataset of nearly 22,000 calibrated years (±18,400 14C years) and includes corrections to previously used data sets. The program is menu-driven and can be used to calibrate 14C ages, provide Δ14C series, and display results. It is compatible with IBM-compatible computers and can also be obtained for Macintosh upon request. The paper discusses the selection of calibration data and new features of the CALIB 3.0 program, including the handling of bidecadal and decadal data sets, marine samples, and atmospheric samples older than 10,100 (10,500) 14C years. The program allows for the calculation of calibrated ages, age ranges, and probability distributions, and includes options for error correction and statistical analysis. The paper also provides detailed information on the calibration curves and the graphical outputs available in the program.