Log Burner Size Calculator
A wood burning stove that's too small will never bring a room up to temperature, while one that's too large forces you to run it inefficiently just to avoid overheating. The right kW rating depends on your room's volume and how well it retains heat. Enter your dimensions below for a starting point when shopping for a stove.
Find the right stove size for your room
Enter your room dimensions and how well insulated the room is.
Typical older UK home with some draughts
For a 48.0m³ room, you need a stove rated at approximately:
4.0kW
Look for a stove rated around 4kW — stoves are usually sold in whole or half kW sizes, so round up rather than down.
Recommended products
A few well-reviewed log burners at a range of kW outputs.
£449.00
Pros
- Compact 5kW output suits smaller UK living rooms
- Airwash system keeps the glass door clear of soot
- DEFRA approved for use in smoke control areas
Cons
- Professional HETAS installation strongly recommended
£899.00
Pros
- DEFRA approved for burning wood in smoke control areas
- Large glass window with a clean, classic cast-iron look
- High-efficiency burn cuts log consumption versus open fires
Cons
- Professional HETAS installation strongly recommended
£1249.00
Pros
- Burns both wood and smokeless coal for year-round flexibility
- Frameless crystal glass door for a contemporary look
- DEFRA approved EcoDesign clean-burn efficiency
Cons
- Top price point in the range — a specialist installer quote is worthwhile
Frequently asked questions
Why does an oversized stove cause problems?
An oversized stove overheats the room quickly, forcing you to run it on a low, smouldering burn to compensate. Low, cool burns produce more smoke and tar, which builds up as creosote in the flue and increases the risk of a chimney fire — so bigger isn’t always better.
Do I need a survey before buying a stove?
This calculator gives a solid starting estimate, but UK building regulations and most installers will carry out a proper heat loss calculation before fitting a stove, factoring in wall construction, window area, and ceiling height precisely. Use this figure to shortlist stoves, then confirm with your installer.
What if the room is open-plan and connects to other rooms?
Add the volume of connected, open spaces to your total room volume before calculating, since heat will circulate between them. Just note the estimate assumes reasonably even airflow between the spaces.
Can a log burner heat more than one room?
Some stoves come with a boiler back that can feed radiators elsewhere in the house, but a standard stove primarily heats the room it sits in and adjoining open-plan space through air circulation.