BTU Calculator for Home Heating

Calculate the Required BTUs for Your Home's Heating System

Understanding BTU Calculations

What is a BTU?

A British Thermal Unit (BTU) measures the energy needed to heat one pound of water by one degree Fahrenheit. For home heating, we use BTUs per hour (BTU/h).

Climate Zones

Your climate zone significantly impacts heating requirements. Colder zones need more BTUs per square foot:

  • Zone 1 (Hot): 30-35 BTU/sq. ft.
  • Zone 2 (Warm): 35-40 BTU/sq. ft.
  • Zone 3 (Moderate): 40-45 BTU/sq. ft.
  • Zone 4 (Cool): 45-50 BTU/sq. ft.
  • Zone 5 (Cold): 50-60 BTU/sq. ft.