BTU Calculator

Step 1

Width X Length X Height = N0 of feet³

Step 2

Outside Temperature - Inside Temperature = Difference in Degrees

Step 3

Difference in Degrees ° & Factor

Step 4

Select R Factor:

Well insulated = Factor 2 Enclosed area with windows and walls installed. Partly insulated = Factor 4 Walls installed, no insulation. Doors and windows covered with tarps. Poorly insulated = Factor 7 Most walls installed. Not insulated = Factor 8.5 Main walls not installed, area enclosed by tarps.

Step 5

ft³ X Difference Factor X R Factor = BTU's