Propane vs Natural Gas: Which Fuel Is Right for Your Home?
If you're building a new home, switching heating systems, or just wondering whether your current fuel makes financial sense, the propane vs natural gas debate is one worth settling. Both are reliable fuels that power furnaces, water heaters, stoves, and dryers — but they differ in cost, availability, efficiency, and convenience in ways that matter for your wallet.
Let's break down the real costs, the efficiency math, and help you figure out which fuel makes sense for where you live and how you use energy.
Cost Comparison: The Numbers That Matter
| Factor | Natural Gas | Propane |
|---|---|---|
| Fuel Cost | ~$1.50 per therm | ~$2.50 per gallon |
| BTU per Unit | 100,000 BTU/therm | 91,500 BTU/gallon |
| Cost per 100,000 BTU | $1.50 | $2.73 |
| Avg. Annual Heating Cost | $700–$1,200 | $1,200–$2,500 |
| Connection/Setup | $0–$2,000 (utility line) | $500–$3,000 (tank install) |
| Monthly Service Fee | $10–$25 (utility charge) | $0 (own tank) / $50–$100 (rental) |
| Equipment Cost | Same for both | Same for both |
On a straight cost-per-BTU basis, natural gas is about 45–50% cheaper than propane. For a typical home that uses 60 million BTU per year for heating, that's the difference between roughly $900 and $1,640 annually. Over 20 years, that adds up to $15,000+ in savings with natural gas.
BTU Efficiency: It's Not Just About Price
Here's something most comparisons miss: propane actually burns more efficiently than natural gas. Propane delivers about 2,516 BTU per cubic foot versus natural gas's 1,030 BTU per cubic foot. In practical terms, propane appliances often run at 90–98% efficiency while natural gas appliances typically hit 89–95%.
What does that mean for you? You need less propane by volume to produce the same heat. But because propane costs so much more per BTU, the higher efficiency doesn't close the gap. Natural gas still wins on total operating cost in most scenarios.
For a full rundown on heating system costs and options, check our HVAC replacement cost guide.
Availability: The Urban-Rural Divide
This is often the deciding factor, because it might not actually be your choice to make:
- Natural gas is available to about 50% of U.S. homes through underground utility pipelines. If you're in a city or suburb, you probably have access. If you're rural, you probably don't.
- Propane is available anywhere — it's delivered by truck and stored in a tank on your property. It's the default choice for rural homes and areas without gas infrastructure.
If natural gas is available at your property, it almost always makes financial sense to use it. The monthly cost savings add up quickly, and you never have to worry about running out — it's piped in continuously. If natural gas isn't available, propane is your best non-electric option.
Installation and Setup Costs
Natural Gas
If your home is already near a gas main (common in urban/suburban areas), connecting typically costs $0–$2,000. Many gas utilities will extend service for free or at reduced cost to gain a new customer. If the gas main is far from your property line, the cost can jump to $5,000–$10,000+ for the line extension, which sometimes makes propane more practical.
Propane
You'll need a propane tank — either purchased ($1,500–$3,000 for a 500-gallon tank) or rented ($50–$100/month from the propane supplier). Tank installation runs $500–$1,500 for labor and permitting. Underground tanks cost more to install ($1,500–$3,000 for labor) but keep your yard looking clean.
Many propane suppliers offer "free" tank installation if you sign a multi-year supply contract. These deals lock you into buying propane from that specific supplier, often at slightly above-market prices. Do the math before committing — sometimes buying your own tank and shopping around for propane each year saves more.
Appliance Compatibility
Most gas appliances (furnaces, water heaters, stoves, dryers, fireplaces) come in both natural gas and propane versions. The good news: converting between the two is usually possible. The bad news: it's not free.
Converting a furnace from natural gas to propane (or vice versa) typically costs $150–$500 for a conversion kit and a technician's time. Stoves and dryers are easier — often just a $20–$50 orifice swap. Water heaters sometimes need full replacement depending on the model.
If you're switching fuel types in an existing home, budget $500–$2,000 total to convert all your appliances. It's a one-time cost that pays for itself if you're moving to cheaper fuel.
Safety Comparison
Both fuels are safe when properly installed and maintained, but there are differences worth knowing:
- Natural gas is lighter than air, so leaks dissipate upward and outdoors more easily. Utility companies add mercaptan (that rotten egg smell) so you can detect leaks. Gas line leaks are rare but can cause explosions — carbon monoxide detectors are essential.
- Propane is heavier than air, so leaks settle in low areas (basements, crawl spaces) where they can accumulate. This makes propane leaks slightly more dangerous if undetected. Propane also has mercaptan added for detection. Tank inspections should happen annually.
Both fuels require carbon monoxide detectors and regular appliance maintenance. Neither is inherently "dangerous" — the risks are manageable with basic precautions. Get your furnace inspected annually regardless of fuel type. See our seasonal maintenance checklist for more on keeping your systems safe.
Environmental Impact
If environmental footprint factors into your decision: natural gas produces about 117 lbs of CO2 per million BTU, while propane produces about 139 lbs per million BTU. Natural gas is slightly cleaner-burning, though both are significantly cleaner than oil or coal heating.
That said, natural gas infrastructure involves methane leakage during extraction and transmission, which is a potent greenhouse gas. Propane doesn't have this transmission loss issue since it's stored and delivered in sealed containers. The full lifecycle environmental comparison is closer than the combustion numbers suggest.
Conversion Costs: Switching Fuel Types
Thinking about switching from propane to natural gas (or the reverse)? Here's what the full conversion typically costs:
- Gas line extension to your home: $0–$5,000+ depending on distance from the gas main
- Internal gas piping: $500–$2,000 if existing propane lines need modification
- Appliance conversion kits: $150–$500 per appliance
- Propane tank removal: $200–$500 if switching away from propane
- Permits and inspections: $100–$300
Total conversion budget: $1,000–$8,000. At $500–$1,500/year in fuel savings by switching to natural gas, most conversions pay for themselves within 2–8 years.
The Bottom Line
Choose Natural Gas if:
- It's available at your property (this is the biggest factor)
- You want the lowest ongoing fuel costs
- You prefer continuous supply without tank monitoring
- You're in an urban or suburban area
Choose Propane if:
- Natural gas isn't available in your area
- You prefer energy independence (no utility connection)
- You live in a rural area where gas line extension is prohibitively expensive
- You want higher BTU output per unit for specific applications
For most homeowners with access to both, natural gas wins on cost. But propane is a solid, reliable fuel that keeps millions of rural homes comfortable year-round. Either way, investing in a high-efficiency furnace (95%+ AFUE) will cut your fuel costs regardless of which type you burn. Check our HVAC system comparison guide for help choosing the right heating equipment.