BTU Calculator

Find the Perfect Heater for Your Room in Just a Few Clicks

Want to warm up your space efficiently? Our free BTU Calculator makes it simple. Enter your room dimensions, insulation type, outdoor temperature, and your desired indoor temperature, and the tool instantly calculates the number of BTUs you’ll need. Whether you’re heating a small room or a large building, it gives you accurate results to help you choose the right heater.

Step 1:

Calculate the number of cubic feet to heat

x
x
Number of Square Feet Equals 0 pi
Step 2:

Calculate the the temperature difference factor (C)

−
Difference factor = max(0.20, abs(indoor - outdoor) / 37.5)
Difference (C) = 0
Difference Factor = 0.20
Step 3:

Calculate the Insulation Factor of the Space to Heat

Insulation Factor = 2.00

Calculate the Required Number of BTUs

Number of Square Feet
0 pi
x
Temperature difference factor
0.20
x
Insulation Factor
2.0
=
Required Number of BTUs
0