Propane and natural gas deliver heat at the same energy unit, the British thermal unit (Btu), but their cost per Btu varies due to fuel price, delivery, and efficiency. This article compares typical U.S. prices and shows how cost per Btu translates into monthly and project-level budgeting. Readers will see clear cost ranges to help choose between propane and natural gas based on price per Btu.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Propane price | $2.00/gal | $2.75/gal | $3.50/gal | Typical North American retail; varies by season and supplier |
| Natural gas price | $1.00/therm | $1.50/therm | $2.00/therm | Regional differences; market fluctuations |
| Propane cost per 100k BTU | $2.18 | $3.00 | $3.83 | Derived from price per gallon ÷ 91,600 BTU |
| Natural gas cost per 100k BTU | $1.00 | $1.50 | $2.00 | Per therm price; 100,000 BTU per unit |
| Delivery/Equipment considerations | $0–$20 | $5–$15 | $20–$40 | Includes meters, regulators, lines |
| Annual fuel cost (typical 60 MMBtu/year usage) | $60,000 | $90,000 | $120,000 | Assumes 1,000,000 BTU/hour, seasonal use |
| Per-year savings potential | Varies | Moderate with gas line access | High with efficient appliances | Depends on appliance efficiency and usage |
Assumptions: regional pricing, standard household appliances, no significant leaks, steady usage throughout winter.
Overview Of Costs
Costs to operate heating with propane or natural gas hinge on fuel price per energy unit, delivery infrastructure, and appliance efficiency. Propane requires on-site storage, which increases handling costs, while natural gas benefits from existing pipeline delivery. The table above shows total ranges for common U.S. price scenarios and per-100k-BTU pricing to simplify direct comparisons. For a typical home using 60 MMBtu annually, annual fuel costs can differ by hundreds of dollars monthly depending on the fuel choice and seasonal demand.
Cost Breakdown
Fuel price, delivery charges, and appliance efficiency drive most of the cost difference. The breakdown below focuses on energy costs and practical add-ons you may encounter when budgeting for either fuel. The table combines totals and per-unit pricing to help translate fuel choices into project numbers.
| Category | Propane (low) | Propane (avg) | Propane (high) | Natural Gas (low) | Natural Gas (avg) | Natural Gas (high) |
|---|---|---|---|---|---|---|
| Fuel price | $2.00/gal | $2.75/gal | $3.50/gal | $1.00/therm | $1.50/therm | $2.00/therm |
| Delivery/Service fees | $0–$20 | $5–$15 | $20–$40 | $0–$15 | $5–$20 | $20–$40 |
| Equipment depreciation | $30–$60/year | $40–$70/year | $60–$120/year | $0/year (existing line) | $0–$40/year | $40–$80/year |
| Maintenance | $10–$25/year | $15–$30/year | $25–$50/year | $8–$20/year | $12–$25/year | $20–$40/year |
| Taxes & permits | $0–$5 | $0–$10 | $0–$15 | $0–$5 | $0–$10 | $0–$20 |
| Total annual cost (typical use) | $60–$90/month | $90–$140/month | $120–$240/month | $30–$80/month | $60–$120/month | $100–$260/month |
data-formula=”annual_fuel_cost = (price_per_unit × units) + delivery + maintenance”> Assumptions: standard 60 MMBtu/year usage, typical home, average efficiency appliances.
Factors That Affect Price
Fuel price volatility and regional infrastructure are the main price drivers. Propane prices swing with crude markets and seasonal demand, while natural gas prices track regional supply, weather, and utility tariffs. Appliance efficiency, burner stability, and conversion or connection costs also influence the effective cost per Btu, especially when comparing retrofits or new installations.
Ways To Save
Choose high-efficiency equipment and optimize fuel usage to reduce per-Btu costs. Options include upgrading to high-efficiency furnaces or boilers, sealing ducts, and ensuring proper thermostat calibration. In some regions, rebates or seasonal promotions can offset higher initial costs for either fuel system. Consider long-term maintenance plans that minimize efficiency loss over time.
Regional Price Differences
Prices vary by market area, affecting propane and natural gas differently. In the Northeast, propane often carries higher seasonal demand costs, while in the South and West, natural gas access via pipelines can reduce per-Btu pricing. Urban, suburban, and rural areas show distinct deltas due to distribution networks and local taxes. The following snapshot illustrates typical regional spreads.
- Urban: natural gas often cheaper per Btu than propane due to dense pipeline networks; propane costs reflect delivery logistics and storage.
- Suburban: moderate differences; natural gas usually advantages from consistent supply, propane remains a viable backup or remote option.
- Rural: propane can be more predictable in pricing when natural gas lines aren’t available; delivery charges may be higher, increasing per-Btu cost.
Real-World Pricing Examples
Three scenario cards help translate theory into expected quotes.
Basic: 60 MMBtu/year, old furnace, propane heat
Specs: propane furnace, standard vents, no solar or renewables; labor 6 hours; price per gallon $2.25; setup in a rural area. Total: $2.25/gal × X gallons + delivery + install. Estimated range: $2,000–$5,000 installed.
Mid-Range: 60 MMBtu/year, mid-efficiency system, natural gas
Specs: mid-efficiency gas furnace, duct sealing, thermostat upgrade; labor 8–12 hours; price per therm $1.50. Total: $1.50/therm × X therms + delivery/permit. Estimated range: $3,500–$7,500 installed.
Premium: high-efficiency system, propane backup with natural gas available
Specs: high-efficiency condensing furnace, gas line upgrade, smart controls; labor 12–16 hours; propane price $2.75/gal, natural gas access; total project: $6,000–$12,000 installed.
In practice, a homeowner weighing propane vs natural gas should compare ongoing fuel costs, not just installation. Accounting for efficiency ratings and expected usage days gives a clearer annual cost picture.