Welcome to the NAPA Greenhouse Gas Calculator v5

NAPA's Greenhouse Gas (GHG) Calculator allows users to evaluate greenhouse gas emissions related to asphalt pavement manufacturing in a gate-to-gate analysis. The web-based software tool is free to use.

The user-friendly interface provides a list of typical fuels that are linked to GHG emission factors. GHG emissions are expressed as carbon dioxide equivalents (CO₂e), the universal measure of greenhouse gas emissions in terms of global warming potential.

The GHG Calculator provides inputs for separate fuels used by a rotary dryer plus additional fuels used inside the facility by equipment, including vehicles. A final category addresses CO₂e attributed to electrical use, with location-specific factors to account for the different types of power generation used in each region of the country. Fuel used for onsite power generation can be entered in the Equipment & Vehicles section. Generally, the more fuel combusted or burned, the higher the CO₂e emissions.

Version 5 uses most of the same assumptions, calculations, and emission factors as the previous version. The biggest change is that it was migrated to a new format in 2020 because the Flash-based format of the previous version will become obsolete in 2021. It should also be noted that the GHG Calculator uses a different set of system boundaries, assumptions, and emission factors than the Emerald Eco-Label environmental product declaration (EPD) tool, so the results from the two tools are not directly comparable. A detailed account of how the GHG Calculator works can be found in the GHG Calculator User Manual.