There is no single national price for a 20 lb grill-tank refill. Cost depends on local propane retail rates, whether you refill by weight or buy an exchange, taxes, and shop minimums. Here is an honest way to estimate — using public price sources, not invented numbers.
How much propane fits in a “20 lb” tank?
A common DOT 20 lb cylinder is often described by the propane industry as holding about 4.7 gallons when filled to the typical safe fill level (around 80% of water capacity). Always follow the tank’s stamped capacity and the filler’s scale — overfilling is dangerous.
Use official price reports (not a guess on this page)
- EIA residential propane: The U.S. Energy Information Administration publishes weekly residential propane prices (dollars per gallon, excluding taxes) during heating season and related series year-round. Check the latest U.S. and state figures here: EIA Residential Propane Weekly Prices and the overview at Heating Oil and Propane Update.
- AFDC Alternative Fuel Price Report: DOE’s Clean Cities report snapshots retail alternative fuel prices, including propane, by region: AFDC fuel prices.
A simple estimate formula
Estimated refill ≈ (gallons put in) × (price per gallon) + shop fees.
Example method only: if a station puts about 4.5 gallons into your cylinder and the local posted propane rate is the number you looked up on EIA or AFDC for your area, multiply those two. We intentionally do not print a single dollar total here because it would go stale within weeks and vary by ZIP code.
Or skip the arithmetic and use our propane refill cost calculator (EIA state prices, editable $/gal). Then call a nearby station from our directory for today’s refill price.