Thinking about wood heat for your RV, yurt, hunting cabin, or other tiny space? Great! Wood stoves can provide affordable, clean, and renewable heat all winter long. The first step is determining how many BTU’s you need to heat your space.
What is a BTU?
A BTU is a British Thermal Unit, a unit of measure which is the amount of energy needed to cool or heat one pound of water by one degree Fahrenheit. Heaters are typically rated in either BTU/hr or kW (kilowatts). 1 kW is about 3,412 BTU/hr.
How many BTU’s do I need?
Figuring out how many BTUs you actually need—and how that translates to the right stove—can be tricky. Most BTU calculators and common formulas (like 15 × volume = required BTUs) tend to overestimate for small spaces. That often leads to choosing a stove that’s too large.
Oversizing might work fine with electric or gas heaters where you don't want to max out their capacity, but wood stoves are different. You can’t turn them down much without creating a smoky, low-temperature fire that builds up creosote and risks a chimney fire. If your stove is too big, you’ll either overheat your space or avoid using it altogether.
In fact, the most common complaint we hear from owners of wood stoves, both in tiny spaces and traditional homes, is that they can't build a fire in their stove without making their space uncomfortably hot! A wood stove should be something you enjoy using—not something you avoid.
The solution, of course, is choosing one that’s sized just right. A well-matched stove will keep you comfortable through chilly mornings, cold winter nights, and every cool day in between.
Which size stoves will work for my space?
BTUs are just one piece of the puzzle. To pick a stove that works well in your setup, you’ll also want to consider the type of structure you’re heating, how you’ll use the stove, and which features matter most to you. We’ve put together a full guide to help you find the right wood stove for your small space—whether you’re after efficient heat, a way to cook, or just some cozy ambiance. Read the full stove selection guide →
As always, if you need some guidance with your project, drop us a line at support@tinywoodstove.com and we'll be happy to help!
Dwarf Stove Sizing Chart
Size required for a 31′ Airstream
Hey Spence-
You’re probably looking at the smallest or second-smallest Dwarf stove for a 31 foot Airstream, depending on where you spend the Winter. Drop me a line at support@tinywoodstove.com and we can work out which stove will be best for your situation.
Are the doors of all your units airtight?
Hi Tomlinson-
Yes, our Dwarf stoves have an airtight design, so you can easily control the stove’s burn rate with the built-in air controls. Designs that are less airtight will require a damper in the flue to keep the draft from getting out of control, and tend to be a lot less efficient heaters.
Which product for a spray foamed 16×40 lofted shed house? Looking for stove and oven combo
Hi Rachelle! I’d be happy to help you figure out the right stove for your space. It’s going to depend on how cold it gets where you’re located, the interior height of your shed, and what you’re using it for. I’ll send you a direct message from support@tinywoodstove.com so we can talk about your project.
Where I live , we take the square footage of the space and multiple times 45…. 50 with vaulted ceiling or single paine windows. I’m thinking about one of these for my small off grid bunk room 10,000′ in elevation. It’s only 100 square feet , with vaulted ceiling…so Xs 60 for this place.
I’ve seen formulas like that for HVAC calculations and they can work if you know the BTUs required to achieve your desired temp rise. Our calculator does something simliar in that it takes your structure’s volume and then calculates the btus necessary to achieve the temp rise based on the winter temp and inside temp you input. It then applies that BTU range to our various stove outputs to provide a stove suggestion.