Most backyard grills run on a DOT 20 lb cylinder. When it’s empty you either refill by weight or exchange at a store cage. Those are different products and prices.
What’s in a “20 lb” tank?
Industry and AFDC-oriented explainers commonly treat a filled 20 lb cylinder as holding on the order of ~4.7 gallons of propane at the normal safe fill (about 80% of the cylinder’s water capacity). Always follow the stamp on your tank and the attendant’s scale — overfilling is unsafe. Our calculator uses 4.24 lb per gallon to convert labeled cylinder weight to gallons; try it for a 20 lb tank: open calculator.
Refill vs exchange
Weight refills bill for gallons actually added. Cage exchanges charge a flat fee for a marketed fill amount disclosed by the retailer. AFDC does not always label “exchange only,” so call and ask. Full explainer: refill vs exchange.
Estimating cost (honestly)
There is no single national grill-refill price. EIA publishes residential (home heating) propane in $/gal — useful as a floor, not a store quote. Latest U.S. and state charts: propane prices. Source table: EIA weekly residential propane.
More detail: How much does a 20 lb refill cost?
Before you light the grill
- Inspect hoses and connections; check for odorant smell (rotten-egg additive).
- Keep the cylinder upright outdoors; don’t store filled tanks in living spaces.
- Replace damaged valves, heat-scarred, or out-of-date cylinders.
Safety hubs: NFPA, CPSC, our safety basics.
Find a station near you
Open the nationwide map and click Use my location to center nearby AFDC propane stations. Or jump to busy state hubs:
- Texas · California · Florida
- Ohio · Michigan · Pennsylvania