For over 40 yrs we compiled egg length, egg width, and egg mass data for turtles in order to estimate the latter from published and unpublished data for the 2 former variables. The resulting data set includes nearly 18,000 eggs for 122 species and includes species-specific graphs (with linear regression equations and correlation coefficients) of egg width vs. egg mass and egg width vs. egg mass, as well as multiple regression equations of egg mass as a function of egg length and egg width (with statistical support). It is our hope that this note will stimulate authors to report egg mass data more rigorously, but also facilitate contemporary studies of reproductive strategies in turtles with more complete and accurate data.