Run Costs4 min read
Indoor Fuel Cost Per Hour: Kerosene vs Propane vs Natural Gas vs Electric
Cost per usable kWh for every common indoor heating fuel, with the arithmetic shown so you can redo it at your own prices.
Run Costs
Cost per hour and cost per kWh for every common indoor fuel, with the arithmetic shown so you can redo it at your own prices.
Almost every fuel comparison you will read online is wrong in the same way: it compares prices in units that cannot be compared. A gallon of propane and a gallon of kerosene hold very different amounts of energy, so price per gallon tells you almost nothing about the cost of staying warm.
The only figure worth comparing is cost per usable kilowatt-hour, and it takes one line of arithmetic: price per unit, divided by the energy content of that unit, divided by the efficiency of the appliance. Run it and the popular ranking changes. Portable fuel heaters land mid-table rather than cheap, mains gas beats them comfortably, and a heat pump beats everything — while resistance electric heating, the thing portable heaters are usually compared against, is the most expensive option on the list.
The guides here show the arithmetic rather than just the conclusion, because fuel prices move and regional spreads are large. The formula will outlast any table of prices, including ours.
What goes wrong most often
- Comparing fuels by price per litre, gallon or cylinder instead of per usable kWh.
- Ignoring appliance efficiency — an open fire wastes most of what you pay for.
- Forgetting that 'unvented is 100% efficient' assumes you open a window anyway.
- Comparing a portable heater against peak-rate electricity and calling it cheap.
- Confusing the fuel decision with the heating strategy — heating one room saves more than switching fuel.