The Cost of Heat

Cost Comparison: Electric (Resistance) vs Fuels (Natural Gas, Propane, Oil)

Calculates and compares the cost of equivalent heat energy (100,000 BTU) in typical burners.

1. Enter your electric rate in decimal currency (one cent = 0.01) per kilowatt-hour.
Be sure to add applicable taxes.   Find your rate
For example, if your electric rate is 9½ cents per kilowatt-hour, enter 0.095:

2. Enter your cost of fuel using the same decimal currency.
Be sure to add applicable taxes. Select fuel and unit:

3. Enter your fuel burner's efficiency rating (10-100%)*:

*Burner efficiency, numerically equal to output BTU divided by input BTU (x100), will be specified on newer model burners.

  • A non-vented gas-burning space heater will be 95-99% efficient.
  • A typical high-efficiency (vented, condensing) gas-burning central unit will be rated around 90-95%.
  • Free-standing gas-burning vented space heaters will be 60-80% efficient.
  • Older gas-burning central units (vented, non-condensing) will have efficiency ratings in the neighborhood of 70-80%.

  • A typical high-efficiency oil-burning central heating unit will be rated around 85-90%.
  • Older oil-burning units (central or free-standing) will typically be 50-75% efficient.
  • Oil-to-gas furnace/boiler conversions will run in the range of 50-75%.

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The validity of the results of this cost comparison will depend on the validity of your inputs. Enter real numbers to get real results.

(Pay special attention to placement of decimals.)