Propane Tank Sizes Guide
Updated 30 March 2026
Residential propane tanks come in four standard sizes: 120, 250, 500, and 1,000 gallons. The right size depends on how many appliances you run on propane and your annual consumption. Tanks are filled to 80% capacity for safety, leaving room for gas expansion.
120
gallon tank
250
gallon tank
500
gallon tank
1,000
gallon tank
Detailed Tank Size Guide
Everything you need to know about each residential propane tank size.
120-Gallon Tank
Specifications
Costs
Best for: Cooking only, single gas appliance, pool heaters, outdoor kitchens
Typical refill frequency: Once or twice per year for cooking
The smallest residential tank. Cannot power a whole-home furnace. Ideal for supplemental propane use. Easy to place in small yards. Some areas allow these without permits.
250-Gallon Tank
Specifications
Costs
Best for: Cooking + water heater, supplemental heating, mild climate whole-home
Typical refill frequency: 2 to 3 times per year for heating in mild climates
The most popular choice for homes that use propane for cooking and a water heater but not primary heating. Also works as a whole-home tank in very mild climates (Southern US) where heating loads are low.
500-Gallon Tank
Specifications
Costs
Best for: Whole-home heating, heating + hot water + cooking, most common residential size
Typical refill frequency: 2 to 3 times per year for whole-home heating
The standard choice for homes using propane as their primary heating fuel. A 500-gallon tank can power a furnace, water heater, range, and dryer for a typical home. Can be buried underground for aesthetic reasons. Allows you to take advantage of summer fill pricing.
1,000-Gallon Tank
Specifications
Costs
Best for: Large homes (3,500+ sq ft), cold climates, backup generators, commercial use
Typical refill frequency: 1 to 2 times per year for large homes
Required for large homes in cold climates that go through 1,200+ gallons per year. The larger capacity means fewer deliveries and often better per-gallon pricing. Also used for commercial applications and homes with propane-powered standby generators that need extended runtime.
Why Tanks Are Only Filled to 80%
Propane is stored as a liquid that expands significantly with temperature changes. A gallon of propane at 60 degrees F will expand by about 1.5% for every 10 degrees F increase in temperature. On a hot summer day, propane in a full tank could expand enough to create dangerous pressure.
The 80% fill rule (required by NFPA 58 and enforced by all states) leaves a 20% vapor space above the liquid propane. This buffer absorbs expansion safely. A 500-gallon tank will hold a maximum of 400 gallons of liquid propane.
Every tank has an OPD (Overfill Prevention Device) valve that stops filling at 80%. If your delivery driver fills to exactly 80%, this is correct and expected. You are paying for 400 gallons in a 500-gallon tank, and that is the full, safe capacity.
Should You Rent or Buy Your Tank?
Buy Your Tank
- Shop multiple suppliers for the best per-gallon price each delivery
- No annual rental fee ($75 to $200/year savings)
- Tank adds value to your property if you sell
- You control maintenance schedule and tank placement
- Break-even vs renting: typically 5 to 7 years for a 500-gallon tank
- Freedom to switch suppliers if pricing or service declines
Rent Your Tank
- No upfront cost (supplier owns and installs the tank for free)
- Supplier handles all maintenance, inspections, and repairs
- Easy to return if you move or switch to natural gas
- Some suppliers include free leak checks and safety inspections
- Better for short-term living situations (under 5 years)
- No worry about tank depreciation or disposal at end of life
The Hidden Cost of Renting
The biggest downside of renting is supplier lock-in. When you rent, you must buy propane exclusively from the tank owner. This eliminates competition and often results in per-gallon prices 20 to 40 cents higher than the open market. On 1,000 gallons per year of consumption, that is $200 to $400 extra per year on top of the rental fee. Over 10 years, renting can cost $3,000 to $6,000 more than owning for a typical household.
Above Ground vs Underground Installation
| Factor | Above Ground | Underground |
|---|---|---|
| Install cost (500 gal) | $500 to $1,500 | $1,500 to $3,000 |
| Visual impact | Visible in yard | Only dome cap visible |
| Maintenance access | Easy inspection and repair | Requires excavation for major repairs |
| Corrosion risk | Low (above moisture) | Higher (soil contact, requires anode) |
| Temperature stability | Fluctuates with weather | More stable underground temperature |
| HOA compliance | Often restricted or screened | Usually no restrictions |
| Lifespan | 25 to 30 years | 20 to 25 years (corrosion) |
| Available sizes | All sizes (120 to 1,000 gal) | 500 and 1,000 gallon only |