Wildfires are a natural, reoccurring, and essential component of ecological communities worldwide. Decades of fire exclusion and altered fire regimes have had substantial ecological consequences, including increased fuel loads. Fuel loads are diverse in their physical attributes, complex in structure and origin of their components. As the source of all wildland fire behavior and fire effects, carbon sequestration and release, and many ecological and habitat consequences, characteristics of a fuelbed must be quantified in order to operate fire and ecological based fire models. The Fuel Characteristic Classification System (FCCS) is comprised of 3 components: a database of 265+ fuelbeds common to North America that contains size, abundance, physical properties, and, the vertical and horizontal arrangement of fuels across the landscape; an expert system to interactively select fuelbeds from general site data and to adjust fuelbeds in the database; and calculation of relative (normalized to a scale of 0-10) fuelbed fire potentials. Each fuelbed is comprised of data for live and dead fuels in 6 strata: canopy, shrub, non-woody (forbs and grasses), woody, litter, lichen and moss, and ground fuels. Fire potentials, patterned after the fire spread model by Rothermel (1972) are calculated from loading, heat content, bulk density, and thickness of fuel elements. Fire potentials describe the capacity of a fuelbed for surface fire behavior, crowning potential, and fuel consumption. The potentials approximate fire behavior and biomass consumption of oven-dry fuelbeds under no-wind conditions. FCCS is an alternative to stylized fuel models, provides land managers and researchers organized fuels data along with numerical inputs to fire behavior, fire effects, dynamic vegetation, habitat and carbon models, and provides fire potentials to assess fire potential hazards at various scales across the landscape.