Gas and propane stoves emit nitrogen dioxide (NO ₂ ) pollution indoors, but the exposures of different U.S. demographic groups are unknown. We estimate NO ₂ exposure and health consequences using emissions and concentration measurements from >100 homes, a room-specific indoor air quality model, epidemiological risk parameters, and statistical sampling of housing characteristics and occupant behavior. Gas and propane stoves increase long-term NO ₂ exposure 4.0 parts per billion volume on average across the United States, 75% of the World Health Organization’s exposure guideline. This increased exposure likely causes ~50,000 cases of current pediatric asthma from long-term NO ₂ exposure alone. Short-term NO ₂ exposure from typical gas stove use frequently exceeds both World Health Organization and U.S. Environmental Protection Agency benchmarks. People living in residences <800 ft ² in size incur four times more long-term NO ₂ exposure than people in residences >3000 ft ² in size; American Indian/Alaska Native and Black and Hispanic/Latino households incur 60 and 20% more NO ₂ exposure, respectively, than the national average.