Blog / Understanding stove output (kW) and room size
06 March 2026 · 3 min read
Understanding stove output (kW) and room size
Article hero image
A stove’s output is measured in kilowatts (kW). It’s tempting to assume more is better — but an oversized stove is actually harder to live with.
Matching output to the room
As a rough starting point, take the room’s volume in cubic metres and divide by 14 to get a ballpark kW figure. A well-insulated modern room needs less; an old, draughty one needs more.
Run an oversized stove low and you get dirty glass, a sooty flue and wasted fuel. The right size, run properly, is cleaner and more efficient.
- Measure length × width × height for the room’s volume
- Divide by roughly 14 for a rough kW guide
- Adjust for insulation, windows and external walls
We do this calculation properly as part of every free survey, so you end up with a stove that’s genuinely right for the space.
Thinking about a stove?
Get a free, no-obligation quote from your local HETAS team.