How to Calculate Needed BTUs

Heating your home is a necessity during the winter in most parts of the United States.
Knowing the BTU output of heaters helps you heat rooms properly.
This usually results in higher utility bills, especially if you do not understand how to best heat your home. Heaters have expected ratings known as BTUs (British thermal units). You can calculate the BTUs you'll need to heat your home by taking a few measurements and using an online calculator. This will help you plan your heating options for the winter. .

Step 1

Measure the length, width and height (floor to ceiling) of the main room you use every day.

Step 2

Refer to the BTU calculator at the Herman-Nelson website and open a new browser window with this link.

Step 3

Select Fahrenheit or Celsius on the calculator. Enter your target inside temperature and the average low temperature for a specific winter month.

Step 4

Enter the length, width and height of the room you measured. Press “Calculate” to determine the needed BTUs for heating your home.

Step 5

Review the BTU output of heaters and their efficiency. Multiply the BTU output by the efficiency rating; for example, 10,000 BTUs with a 70 percent efficiency rating equals 7,000 net BTU output.

Step 6

Compare the figure from Step 4 and Step 5 to ensure your selected heater is sufficient for heating your room or home.

Things You Will Need

  • Tape measure

About the Author

Daniella Lauren has worked with eHow and various new media sites as a freelance writer since 2009. Her work covers topics in education, business, and home and garden. Daniella holds a Master of Science in elementary education and a Bachelor of Arts in history from Pensacola Christian College.