Body mass is an important, necessary parameter in life history studies. For insects, body mass is hard to obtain for large samples of species that may be distributed worldwide, making comparative studies difficult. Dry weights of museum specimens would be convenient, but specimens are generally inseparable from their pin. Here, I provide curves that allow researchers to estimate the weight of pins based on an empirically-derived model of length, diameter, material and head type (r² = 0.99). Thus, pin weight can be subtracted from total specimen weight, allowing estimation of dry specimen weight. I assess inaccuracy of the method due to uncertainty in pin weight, and discard specimens where this made the dry weight estimate unreliable. This occurred primarily in insects weighing less than twice the 95% confidence interval for the weight of the pin; as a rule of thumb, I show that this method is unsuitable for insects below 11mm long. Among remaining specimens, dry weights agreed well with reported weights of oven-dried conspecifics, but were slightly heavier than predicted based solely on length—possibly indicating shrinkage in length over time. Age had no effect upon specimen weight. This is a quick and easy method for determining insect dry weight with relatively small loss of accuracy, and should greatly facilitate comparative studies of insect life history that require body mass as a covariate.