Estimate annual propane gallons from square footage, climate (heating degree days), and appliance load.
NOAA / weather.gov publishes climate-normal HDD for most US cities.
A typical propane water heater uses ~200–250 gallons/year for a household of four. Set to 0 if you use electric.
estimated annual gallons
956 gal
Annual propane = heating load + appliance load.
Heating uses the standard residential heuristic:
annual heating BTU ≈ sqft × HDD × insulation factor
Then converted to gallons via 91,500 BTU per gallon of propane and a seasonal furnace AFUE of 90% (typical for a modern condensing unit).
Heuristic only — for an exact number, use a Manual J residential load calculation. Insulation factors are common planning approximations, not a code value.
Take this estimate to a real local dealer — enter your ZIP to see who delivers in your area.