What does heating with wood or pellets cost?
The purchase price is only part of the comparison. You also need the fuel’s energy content and the fraction of that energy delivered as useful heat. A cheaper kilogram of fuel is not necessarily a cheaper kWh of heat.
Consider pellets costing 0.35 per kg with 4.8 kWh/kg of fuel energy and 80% stove efficiency. They deliver 3.84 useful kWh per kg, costing about 0.0911 per useful kWh. Delivering 12,000 kWh of heat needs about 3,125 kg and costs 1,093.75. These example values are editable and are not a fuel-quality guarantee.
Convert the bag price first
If a 15 kg bag costs 6.00, enter 0.40 per kg. For a price per metric tonne, choose “tonne”: one tonne is 1,000 kg. A US short ton is different; convert to kilograms or pounds before using this calculator.
Be careful with volume prices
A solid cubic metre, a neatly stacked cubic metre and a loose load do not contain the same mass of wood. For volume pricing, enter the actual kilograms in one purchased cubic metre. Use a supplier’s measurement for the delivery type rather than treating wood density as the mass of a loose load.
For ft³ pricing, the calculator uses 0.028316846592 m³ per cubic foot. The mass input remains kilograms per purchased m³. Pounds are converted using 0.45359237 kg per lb.
Choose realistic energy and efficiency values
Enter fuel energy for the product as supplied, including its moisture condition. Keep the stove efficiency on the same calorific-value basis. A generic default cannot account for wet logs, different species, how the stove is operated or the heat that actually reaches the rooms you want to warm.
The energy calculation excludes electricity for pellet feed motors and fans unless you add an allowance in annual costs. Chimney sweeping, delivery and servicing can also be included there. Use a local suitability assessment for ventilation, emissions and installation requirements.
These are transparent energy-balance calculations. See the methodology and use your fuel supplier’s specifications for your own scenario.