Zooplankton biomass can be estimated through the use of equations that convert length of individuals to dry weight. The logarithmic transformation of these power equations follow the form Ln(W) =Ln(α) + β Ln(L) where L is length in mm, W is dry weight in ug, and α and β are species-specific values. Several sets of L-W equations have been developed for use in the Great Lakes region by agencies such as the Environmental Protection Agency (EPA) and Canada’s Department of Fisheries and Oceans (DFO). Since we collaborate with both agencies and require comparability with previously collected data, we reviewed these two sets of equations and the publications that were used to develop them. We offer a third Cornell Standard (CBFS STD) set that resolves many of the discrepancies seen in the other sets.