Is a Wood Burner Worth It? Payback Calculator

Whether a wood burner is worth it in money terms comes down to three numbers: what it cost to fit, what you pay for logs, and how much of your normal heating it genuinely lets you switch off. This calculator puts them together and gives you a payback period in years, or tells you plainly that it will never pay back on your figures. The insight most sales pages skip: a stove heats one room, so unless your boiler or heaters actually run less, the logs are an extra bill rather than a saving.

How the payback is worked out

The calculator first works out how much heat the stove puts into the room over a season: output in kW, times hours lit, times days and weeks. It then works out the logs needed to make that heat, using the energy in a cubic metre of your chosen wood and your stove's efficiency, and prices them.

Next it takes the share of that heat which genuinely replaces your existing heating and prices it at your fuel's unit rate, allowing for your boiler, heater or heat pump efficiency. The yearly saving is the heating you avoid, minus the logs, minus sweeping and upkeep. Divide the installed cost by that saving and you have the payback in years.

Why the answer is so often "never" on mains gas

Mains gas is cheap per unit of heat, and a condensing boiler wastes little of it. Bought logs, after the heat lost up the flue, frequently cost more per useful kWh than gas does. Run the numbers with your own bills: if the logs cost more per unit of heat than gas, no amount of burning makes the stove pay back. People off the gas grid, on oil, LPG or direct electric heating, are where the sums are most likely to work, as is anyone with a cheap or free supply of wood they can season themselves.

The share figure matters more than you think

A stove in the lounge does not heat the bedrooms. If the thermostat is in the hall and the boiler keeps firing, your stove heat is mostly extra comfort, not a saving. Be honest with the share box: set it high only if you turn the radiators off or down while the fire is lit. Our wood burner running cost calculator shows the cost per useful kWh in more detail, and the firewood price comparison calculator helps you find the cheapest load per cubic metre to push the payback down.

Money is not the only reason to fit a stove. Heat during a power cut, a warm room on demand and the fire itself are real benefits. This tool simply tells you whether the purchase also stands up as a saving, so you can decide with the numbers in front of you.