Propane Tank Sizes & Cost: 120, 250, 500 & 1,000 Gallon Guide (2026)

Purchase price, rental fees, installation cost, dimensions, and the rent-vs-buy breakeven calculation for every residential propane tank size. Updated for 2026 using current supplier and EIA weekly residential propane data.

Latest EIA residential propane price

Source: EIA propane data + current supplier pricing surveys. Current data is the final release of the 2025/26 heating season (week ending 30 March 2026). EIA pauses weekly publication April-September; next release expected October 2026. Refreshed 13 May 2026.

Residential Propane Tank Sizes at a Glance

120 Gallon

Usable capacity96 gal

Fill cost (avg)$267

Purchase price$400-$700

Annual rental$50-$100/yr

Installation$500-$1,200

Dimensions~3.5 ft tall, 2 ft wide

Best for: Cabin or cooking/water only

250 Gallon

Usable capacity200 gal

Fill cost (avg)$556

Purchase price$600-$1,000

Annual rental$75-$125/yr

Installation$600-$1,400

Dimensions~4 ft tall, 2 ft wide

Best for: Small home, supplemental heat

500 Gallon

Usable capacity400 gal

Fill cost (avg)$1,112

Purchase price$800-$1,600

Annual rental$100-$175/yr

Installation$800-$1,800

Dimensions~10 ft long, 3 ft wide

Best for: Most common for whole-home heat

1,000 Gallon

Usable capacity800 gal

Fill cost (avg)$2,224

Purchase price$1,500-$2,800

Annual rental$150-$250/yr

Installation$1,200-$2,500

Dimensions~16 ft long, 3.5 ft wide

Best for: Large homes, multiple propane uses

The 80% Fill Rule: Why Your Tank is Never Completely Full

Residential propane tanks are filled to only 80% of their rated capacity by law (NFPA 58). Propane liquid expands significantly with temperature - up to 17 times its liquid volume as vapor. The remaining 20% vapor space, called the "outage," allows for safe expansion. This is why your 500-gallon tank only receives about 400 gallons per fill, and why your delivery receipt will show 380 to 420 gallons for a nominally "full" 500-gallon tank.

Modern tanks are equipped with an OPD (Overfill Protection Device) valve that automatically stops filling at 80%. This is standard equipment on all tanks made after 1998 and is non-negotiable. All the fill costs shown on this site are calculated using the 80% rule.

Rent vs Buy: The Breakeven Calculation

Factor	Rental	Ownership
Up-front cost	$0	$800-$2,800
Annual rental fee	$75-$250	$0
Supplier flexibility	Locked to one supplier	Shop all suppliers
Per-gallon markup	$0.20-$0.50 extra	Competitive price
Annual savings at 1k gal	Baseline	$200-$500 in fuel
Maintenance	Supplier handles it	Your responsibility
Breakeven point	N/A	3-6 years typically

Example Breakeven Calculation (500-gallon tank)

Assumptions:

1,000 gallons per year usage
$0.30/gal supplier markup when renting
$125/year rental fee
$1,800 tank purchase and installation

Annual cost of renting: $125 rental + $300 markup = $425/year extra

Breakeven: $1,800 / $425 = 4.2 years

After 10 years: Ownership saves approximately $2,450 vs renting. After 20 years: $6,650 in savings.

Above Ground vs Underground Propane Tanks

Factor	Above Ground	Underground
Installation cost	$800-$1,800	$2,500-$5,000
Visual impact	Visible, can be screened with plantings	Invisible above ground
Inspection ease	Easy - visible daily	Requires special equipment
Temperature protection	Exposed to summer heat and winter cold	Protected by earth (stable temp)
Corrosion risk	Surface rust possible over time	Requires special coating; anode protection
HOA/zoning	Sometimes restricted	Often allowed where above-ground is not
Setback requirements	10 ft from buildings (500 gal)	10 ft from buildings
Tank lifespan	30-40 years typical	30-40+ years with proper coating

Our recommendation: Choose above-ground unless you have specific HOA requirements, aesthetic priorities, or are in a climate with extreme temperature swings where underground stability provides meaningful efficiency benefits. The $1,500 to $3,000 in additional installation cost rarely makes sense for most homeowners.

Tank Sizes FAQ

Which propane tank size do I need?

For whole-home heating: 500 gallons is the most common choice for homes using 800 to 1,200 gallons per year. A 1,000-gallon tank suits large homes or those using over 1,200 gallons annually. For cooking and water heating only (no heating): 250 gallons is usually sufficient. For seasonal use (cabin, backup): 120 gallons often works. Size up if in doubt - larger tanks mean fewer fills and often better per-gallon pricing.

How much does a 500-gallon propane tank cost installed?

A 500-gallon above-ground propane tank costs $1,500 to $2,500 to purchase and install, including the regulator, line to the house, and initial inspection. Underground installation costs $1,500 to $3,000 more due to excavation and special coating requirements. Tank purchase alone runs $800 to $1,600. Installation labor is typically $500 to $900 for above-ground work.

Is it better to rent or buy a propane tank?

If you plan to stay in your home for 3 or more years, buying is almost always better financially. Tank ownership lets you shop multiple suppliers, which typically saves $0.20 to $0.50 per gallon. At 1,000 gallons per year, that is $200 to $500 in annual savings. Add the $75 to $150 annual rental fee you eliminate, and a $1,800 tank pays for itself in 3 to 5 years. Renting makes sense only if you are unsure about your long-term residence or if a large up-front cost is prohibitive.

How long does a propane tank last?

Residential propane tanks typically last 30 to 40 years with proper maintenance. They should be inspected annually for corrosion, leaks, and valve condition. Underground tanks, while more expensive to install, are generally better protected from weather-related corrosion and can last even longer. The tank itself does not expire like small cylinders, but components like the regulator and hoses need periodic replacement.

Is above-ground or underground propane tank better?

Above-ground tanks are significantly cheaper to install ($500 to $1,000 vs $2,000 to $4,000 for underground) and easier to inspect and maintain. Underground tanks are preferred aesthetically and are protected from temperature extremes, but require special corrosion-resistant coating and more complex installation. Most residential customers choose above-ground unless local regulations require underground placement or aesthetics are a priority.

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