The U.S. Environmental Protection Agency and Oak Ridge National Laboratory have developed an online calculator called the Vapor Intrusion Screening Level (VISL) Calculator. The calculator provides screening level concentrations for groundwater, soil gas, and indoor air for certain chemicals to help risk assessors evaluate vapor intrusion risks. It calculates screening levels for groundwater and soil gas using conservative attenuation factors from EPA's draft vapor intrusion guidance document. The VISL Calculator can also estimate indoor air concentrations from user-entered soil gas and groundwater data using default attenuation factors. It will provide risk values and be a useful tool for citizens, risk assessors, and risk managers.