Propane vs Natural Gas
Updated 30 March 2026
Natural gas is cheaper per BTU when pipeline access is available. Propane wins on availability, energy density, and independence from the grid. The right choice depends on where you live and whether natural gas service reaches your property.
$3.04
per 100,000 BTU
91,500 BTU per gallon
Available everywhere via tank delivery
$1.20
per 100,000 BTU
100,000 BTU per therm
Requires underground pipeline connection
Bottom Line
Natural gas costs 40 to 60% less per BTU when you have pipeline access. Propane is the clear winner for the 40% of US homes without a gas line, offering reliable delivery to any location. For cooking, both fuels are excellent and cost differences are minimal (under $50 per year).
Full Comparison
Every relevant factor for choosing between propane and natural gas.
| Feature | Propane | Natural Gas |
|---|---|---|
| Fuel type | Liquefied petroleum gas (LPG) | Methane (CH4) |
| Delivery method | Tank delivery by truck | Underground pipeline |
| Average cost per unit | $2.78 per gallon | $1.20 per therm |
| Energy per unit | 91,500 BTU per gallon | 100,000 BTU per therm |
| Cost per 100,000 BTU | $3.04 | $1.20 |
| Furnace efficiency | 90 to 98% (modern) | 90 to 98% (modern) |
| Annual heating cost (avg home) | $2,200 to $3,500 | $900 to $1,500 |
| Availability | Everywhere (tank delivery) | 60% of US homes (pipeline required) |
| Installation cost | $3,000 to $6,000 (furnace + tank) | $2,500 to $5,000 (furnace + connection) |
| Carbon emissions | 12.7 lbs CO2 per gallon | 11.7 lbs CO2 per therm |
| Safety risk | Heavier than air, pools in low areas | Lighter than air, dissipates upward |
| Leak detection | Strong odorant added, easy to detect | Mercaptan odorant added, easy to detect |
| Energy independence | Stored on-site, works during outages | Pipeline dependent, fails in supply disruptions |
| Appliance lifespan | 15 to 20 years | 15 to 20 years |
| Water heater efficiency | Faster recovery, higher BTU output | Slightly slower, adequate for most homes |
Annual Heating Cost Comparison
Estimated annual costs for heating a 2,000 sq ft home in a moderate climate (80 million BTU per heating season).
$2,430
per year
875 gallons at $2.78/gal
95% furnace efficiency
$1,010
per year
842 therms at $1.20/therm
95% furnace efficiency
$3,750
per year
23,440 kWh at $0.16/kWh
100% efficiency (resistance)
Based on 80 million BTU heating load for a 2,000 sq ft home in USDA zone 5-6 (moderate climate). A heat pump at COP 3.0 would reduce electric heating to roughly $1,250/year.
Which Should You Choose?
Rural home, no gas line available
Natural gas is not an option. Propane is the most cost-effective alternative to electric resistance heating. A high-efficiency propane furnace (95%+) will cost significantly less to operate than electric baseboard heaters.
Suburban home with gas line access
Natural gas costs roughly 40 to 60% less per BTU than propane. If a gas line is available, connecting to it will save $1,000 to $2,000 per year on heating costs for an average home.
Backup/emergency heating
Propane is stored on-site and does not depend on a pipeline. During ice storms, earthquakes, or utility outages, propane systems continue to function. Natural gas pipelines can be disrupted.
New construction in gas service area
For new builds with gas line access, natural gas is cheaper per BTU. However, a heat pump may be the most cost-effective choice if you live in a moderate climate (USDA zones 6 to 10).
Cooking enthusiast
Both propane and natural gas provide instant, adjustable flame. Propane burns slightly hotter (2,500 F vs 2,000 F), which some chefs prefer. Most gas ranges can be converted between fuels with a simple jet swap.
Whole-home power with generator
Propane generators are widely available and store fuel indefinitely. Natural gas generators exist but depend on pipeline pressure during emergencies. Propane is the standard for off-grid and backup power.
Can You Switch from Propane to Natural Gas?
Yes, if natural gas pipeline service is available at your property line. The conversion process involves:
What It Costs
- Gas line connection fee: $500 to $2,000 (varies by utility)
- Furnace conversion kit: $150 to $300 (or new furnace: $2,500 to $5,000)
- Appliance conversion (range, dryer, water heater): $100 to $200 each
- Propane tank removal: $200 to $500 (or return to rental company for free)
- Total typical cost: $1,500 to $4,000
Is It Worth It?
If you spend $2,500 per year on propane heating, switching to natural gas at $1,000 per year saves $1,500 annually. A $3,000 conversion investment pays for itself in 2 years. For homes using propane only for cooking ($50 to $100 per year in fuel), conversion rarely makes financial sense. The math depends on your annual propane consumption and local gas utility connection costs.