Ground, surface, and canopy fuel characteristics serve as essential inputs to computer models of fire behavior and fire effects. FuelCalc is a fuel characteristics simulation software application that calculates initial canopy fuel characteristics and quickly simulates the effects of thinning, pruning, piling and broadcast burning on ground, surface and canopy fuel characteristics. Consequently, FuelCalc is useful for planning fuel treatments, as well as for estimating the effects of wildfire on surface and canopy fuel characteristics. FuelCalc works by simulating changes in ground, surface, piled, and canopy fuel loads by size class as fuel treatments add to, or subtract from, the load in each class. The FOFEM, Burnup and Nexus simulation models are used for predicting stand structure and fuel loading changes post fire. FuelCalc input files can be created in the FFI ecological monitoring software (http://www.frames.gov/ffi) or by manually creating an input file in FuelCalc’s standard format.