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Propane Tank Refill Cost: From 20lb BBQ to 1,000-Gallon Home Tank (2026)

Fill costs at the national average ($2.78/gal) with cheapest and most expensive state ranges. Based on the 80% fill rule.

Propane Tank Fill Costs at a Glance (April 2026)

Tank SizeTotal CapacityUsable (80% Rule)Fill Cost (Nat. Avg $2.78)TX $2.18/galHI/VT $4.00+/gal
20 lb BBQ~5 gal~4.7 gal$13$10$19
30 lb portable~7 gal~5.6 gal$16$12$22
40 lb portable~9.4 gal~7.5 gal$21$16$30
100 lb cylinder~23.6 gal~18.9 gal$53$41$76
120 gallon120 gal96 gal$267$209$384
250 gallon250 gal200 gal$556$436$800
500 gallon500 gal400 gal$1,112$872$1,600
1,000 gallon1,000 gal800 gal$2,224$1,744$3,200

Prices based on 80% fill rule (industry standard and NFPA 58 requirement). Actual fill may vary by supplier. 20lb tank usable capacity is the full 20 lbs for refill; exchange gives approximately 15 lbs.

20 lb BBQ Tank: Refill vs Exchange

For BBQ and patio heater owners, refilling at a propane station is almost always cheaper than the exchange programs at Walmart, Home Depot, and most gas stations. Here is why: exchange programs pre-fill tanks to only 15 pounds (for safety/liability reasons) but charge as if the tank were full. Refill stations fill to the full 20 pounds.

OptionCost RangePropane AmountCost per PoundWhere Available
Refill at propane dealer$12-$2020 lbs (full)$0.60-$1.00Propane dealers, U-Haul, some hardware stores
Exchange (Blue Rhino / AmeriGas)$22-$3015 lbs (75% full)$1.47-$2.00Walmart, Home Depot, Lowe's, most gas stations
Costco refill (members)$10-$1420 lbs (full)$0.50-$0.70Costco warehouse locations with refill station
Tractor Supply refill$13-$1620 lbs (full)$0.65-$0.80Tractor Supply Company locations
Full 20 lb Tank Guide (Refill vs Exchange)

Residential Tank Fill Details

120 Gallon
Usable
96 gal
Fill cost
$267
Fill frequency: 3-6x per year for cooking/water heating only. Once if also heating a small space.
Common for vacation cabins, cooking + water heating only.
250 Gallon
Usable
200 gal
Fill cost
$556
Fill frequency: 2-4x per year for home heating. Monthly in cold climates.
Good for small homes or supplement heating.
500 Gallon
Usable
400 gal
Fill cost
$1,112
Fill frequency: 2-3x per year for typical heating homes. Most common residential size.
Most popular for whole-home heating. Good value at bulk pricing.
1,000 Gallon
Usable
800 gal
Fill cost
$2,224
Fill frequency: 1-2x per year. Very large homes or multiple propane appliances.
Best per-gallon price. Requires more installation space.

The 80% Fill Rule: Why Your Tank Is Never Completely Filled

Propane tanks are filled to only 80% of their total capacity. This is required by NFPA 58 (the Liquefied Petroleum Gas Code) and is not a supplier trying to shortchange you. Propane liquid expands significantly with temperature changes - up to 17 times the volume of the liquid. The 20% vapor space (called the outage) allows for this expansion without creating a dangerous pressure buildup.

All modern tanks have an OPD valve (Overfill Protection Device) that automatically stops filling at 80%. This is why your 500-gallon tank only ever holds about 400 usable gallons, and why the fill costs above are calculated on the usable capacity.

Learn more about propane safety and tank requirements

Volume Discounts and Delivery Fees

Volume Discounts (Typical)
Under 100 galNo discount
100-199 galStandard price
200-399 gal$0.05-$0.10/gal off
400+ gallons$0.10-$0.15/gal off

Volume thresholds vary by supplier. Ask specifically what discounts apply at different order sizes.

Delivery Fee Models
All-inclusive pricingMost common
No separate delivery fee. Easier to compare.
Split pricingSome suppliers
$50-$100 delivery fee + lower per-gallon price.
Emergency deliveryOff-schedule
$75-$200 surcharge for same-day or after-hours.
Auto-deliveryBest deal
5-10% discount vs will-call. Supplier monitors tank.
Full delivery guide: auto vs will-call, minimum orders, fees

Refill Cost FAQ

How much does it cost to fill a 500-gallon propane tank?
At the national average of $2.78/gal, filling a 500-gallon tank costs approximately $1,112 (based on the 80% fill rule - tanks are only filled to 400 usable gallons). In the cheapest state (Texas, $2.18/gal), expect to pay around $872. In the most expensive states (Vermont, Hawaii), the same fill can cost $1,580 to $1,660. Most homeowners fill their 500-gallon tank 2 to 3 times per year.
Is refilling a 20lb propane tank cheaper than exchanging it?
Almost always, yes. Refilling a 20lb tank costs $12 to $20 for a full 20 pounds of propane. Exchanges at retailers like Walmart, Home Depot, and most gas stations cost $20 to $30 but only put back 15 pounds (the tanks are pre-filled to 15 lbs for safety compliance). This means you pay about 60% more per pound of propane with an exchange. The exception is if your tank is old, damaged, or has an expired certification - exchange programs accept these whereas refill stations may not.
What is the minimum propane delivery order?
Most residential propane suppliers require a minimum delivery of 100 to 150 gallons. Deliveries below the minimum may incur a surcharge of $25 to $75. Some suppliers offer will-call service with no minimum but charge higher per-gallon prices. Auto-delivery programs typically waive minimums since they schedule deliveries based on your usage patterns.
Why are propane delivery fees sometimes separate from the per-gallon price?
Suppliers use two different pricing models. The all-inclusive model rolls delivery cost into the per-gallon price, which makes comparison shopping easier. The split model shows a lower per-gallon price but adds a separate delivery fee of $50 to $100 per trip. Always ask for the total delivered cost per gallon when comparing suppliers, not just the commodity price.
Tank sizes and purchase costs|State price comparison