Calculator
Propane tank refill cost calculator
How many gallons a fill takes, and what it costs, at today's state price.
Tanks are filled to at most 80% of shell capacity — the 80% rule leaves a 20% vapor space for thermal expansion, and is required by law. Gauge readings are approximate and read percent of that usable volume. Price is the EIA weekly state residential survey figure, prefilled and editable; your delivered price, taxes, and fees vary by supplier and volume. This is arithmetic on the numbers you enter, not a quote.
Cite
Common questions
How much does it cost to fill a 500-gallon propane tank?
A 500-gallon tank holds about 400 gallons at the 80% fill limit. From a 30% gauge that's roughly 250 gallons; multiply by your price per gallon for the cost. Enter your gauge reading and state price above for the exact figure.
Why can't a propane tank be filled to 100%?
Propane expands as it warms. Filling to 80% leaves a 20% vapor space so the liquid has room to expand without over-pressurizing the tank. It is a safety rule, not a short-fill.
How many gallons is 30% on the gauge of a 500-gallon tank?
The gauge reads percent of the tank's usable volume. 30% of a 500-gallon tank is about 150 gallons in the tank; topping to the 80% (400-gallon) limit adds about 250 gallons.