BurnBetter / Plan your firewood
Free UK Firewood Calculator
How much firewood do I need? Use this free UK firewood calculator to estimate how much wood your stove may use per burning hour, day, week and heating season. Adjust the stove output, efficiency and your normal burning routine for a practical estimate in kilograms and tonnes.
Based on BurnBetter’s recommended planning target of 18% moisture content.
Your estimated season
1.04 tonnes of firewoodApproximately 1,042 kg per year
5 kW · 5 hours/day · 7 days/week · 20 weeks/year · 80% efficiency
A planning estimate, not a loading instruction. These figures assume your stove delivers the selected output throughout the hours entered.
Behind the numbers
Heat in. Useful warmth out.
We assume approximately 4.2 kWh of fuel energy per kilogram at an 18% moisture target. Efficiency accounts for how much of that energy becomes useful heat.
kg/hour = stove output ÷ (4.2 × efficiency)
Daily use multiplies this by your burning hours; weekly use by your days; seasonal use by your weeks. Tonnes are kilograms divided by 1,000.
Make the estimate useful
Buy by weight. Check your fuel.
Actual use varies with species, moisture, weather, chimney draught, lighting technique and how you run the stove. The 18% figure is a planning target, not a measurement of your logs.
Check a freshly split inner face with a moisture meter. For a better buying plan, weigh what you actually use over a typical week and compare it with the estimate.
Firewood calculator FAQs
Common questions about seasonal firewood use
How much wood does a 5 kW stove use per hour?
Using this calculator’s 18% moisture planning assumption and an 80% efficient stove, a continuous 5 kW output works out at about 1.49 kg of firewood per burning hour. Real-world use varies because a stove does not normally run at its rated output every minute.
How much firewood do I need for winter?
That depends mainly on how many hours you burn each day, how many days per week you use the stove, the length of your heating season and the heat output you actually require. Enter your own routine above for a personalised seasonal estimate.
Does hardwood or softwood change the result?
At a similar moisture content, the useful energy per kilogram is broadly comparable. Hardwood is generally denser, so the same weight usually takes up less storage space, while softwood may occupy more volume.
Why does the calculator use 18% moisture content?
BurnBetter uses 18% as a practical dry-firewood planning target. Your actual logs should always be checked correctly with a moisture meter on a freshly split inner face.
This calculator is general planning guidance. It does not size a stove for your home or prescribe refuelling amounts or intervals. Always follow your appliance manufacturer’s fuel, loading, air-control and maintenance instructions. Never overload or deliberately slumber a stove to match an estimate.
Estimates are not a guarantee of consumption, cost or performance. Read the BurnBetter disclaimer.