Compare electric and propane patio heater costs per hour, per season, and over the years you plan to own them.
Use pattern
Local energy prices
Purchase and ownership
Advanced options
One-time setup costs
Propane service charges
Calculation details
Table of contents
How to use our Electric vs Propane Patio Heater Lifetime Cost Calculator
- Enter the product-label Electric heater power in watts and Propane heat input in BTU/h, plus the number of heaters you would run.
- Describe your use pattern with Hours each time, Times used each month, and Months used each year.
- Replace the default Electricity price and Propane price with the usage-based rates from your bill, receipt, or supplier quote.
- Enter each heater's purchase price and your Planned ownership period. Open Advanced options only for installation, tank, service, or refill charges that apply.
- Check Estimated heater hours per year and the Propane-to-electric rated input ratio before using the lower-cost result. Very different ratings do not mean the heaters provide equal outdoor warmth.
Definitions
BTU/h: British thermal units per hour. This is a rate of heat input, often shown on a propane heater label.
kWh: Kilowatt-hour, the electricity unit used for billing. A 1,000 W heater running for one hour uses 1 kWh.
Electricity price: The usage-based cost of one kWh. Fixed customer charges are not part of this rate.
Propane price: The fuel-only price of one gallon of propane. A refill, exchange, or delivery fee belongs in its separate fee field.
Estimated heater hours per year: Hours each time multiplied by times used each month and months used each year.
Propane-to-electric rated input ratio: Propane BTU/h divided by the electric heaters' combined input converted to BTU/h. The watts-to-BTU/h conversion is 3.412141633 BTU/h per W. [1]
Common mistakes and quick fixes
Mistake: Entering a propane cylinder's total capacity in Propane heat input.
Fix: Enter the heater's fuel input rating in BTU/h from its label or manual, such as 48,000 BTU/h.
Mistake: Typing the full price of a cylinder exchange into Propane price.
Fix: Use the fuel price per gallon. Put an added exchange or delivery charge in Propane fee per refill or delivery.
Mistake: Including a fixed monthly utility customer charge in Electricity price.
Fix: Use the usage-based price per kWh that changes when the heater uses more electricity.
Mistake: Entering the total price for several units in Electric heater purchase price or Propane heater purchase price.
Fix: Enter the price of one heater; the calculator multiplies it by the number of heaters.
Mistake: Treating a high Propane-to-electric rated input ratio as proof that one heater feels warmer.
Fix: Use the ratio only to spot unequal rated inputs. Wind, distance, placement, and heater design can change outdoor comfort.
Limitations & Key Assumptions / Boundary Conditions
- The comparison uses listed maximum electric power and propane heat-input ratings. Actual use can be lower when a heater cycles, has adjustable settings, or is turned off early.
- It compares cost, not equal warmth. Wind, air temperature, mounting height, distance, coverage area, and radiant design can make differently rated heaters feel very different outdoors.
- Energy prices, propane fees, and use patterns are held constant for the selected ownership period. Fuel-price changes, taxes, time-of-use electric rates, and inflation are not modeled.
- Heater repairs, replacement, maintenance, resale value, permits, and electrical capacity upgrades are excluded unless you add a quoted one-time installation cost.
- Transaction fees are estimated by rounding propane use up to whole refills or deliveries. Enter the gallons actually received per paid transaction when that fee applies.
Methodology
Runtime and hourly energy cost
The calculator first estimates yearly runtime from your patio schedule.
annual_heater_hours = hours_per_use * uses_per_month * months_per_year
Electric cost uses the combined watt rating, converted from watts to kilowatts, then multiplied by your electricity price.
electric_energy_cost_per_hour = electric_watts * electric_heater_count / 1000 * electricity_price
Propane use converts the combined BTU/h fuel-input rating into gallons using 91,452 BTU per gallon [1]. Propane fuel cost then uses your entered price per gallon.
propane_gallons_per_hour = propane_btu_per_hour * propane_heater_count / 91452
propane_fuel_cost_per_hour = propane_gallons_per_hour * propane_price
Lifetime totals
Electric lifetime cost includes heater purchases, optional electrical installation, and seasonal electricity cost for the planned ownership period. Propane lifetime cost includes heater purchases, optional setup, seasonal fuel, annual service charges, and any refill or delivery fees.
electric_lifetime_cost = electric_purchase_price * electric_heater_count + electric_installation_cost + electric_season_energy_cost * ownership_years
propane_lifetime_cost = propane_purchase_price * propane_heater_count + propane_setup_cost + (propane_season_fuel_cost + propane_annual_fixed_charge) * ownership_years + propane_lifetime_transaction_cost
If a refill or delivery fee is above $0, estimated lifetime propane gallons are divided by Propane received each refill or delivery and rounded up to a whole transaction before the fee is added.
lifetime_cost_difference = abs(electric_lifetime_cost - propane_lifetime_cost)
Worked example
With one 1,500 W electric heater used 3 hours at a time, 4 times per month, for 6 months, yearly runtime is 72 hours. At $0.1844 per kWh, its electricity cost is $0.2766 per hour and $19.92 per patio season before purchase or installation costs.
The rated-input comparison converts electric watts to BTU/h, then divides propane input by electric input. It is provided only to show whether the products have very different listed input ratings.
rated_input_ratio = (propane_btu_per_hour * propane_heater_count) / (electric_watts * electric_heater_count * 3.412141633)