- 1). Measure the width and length of the room with the tape measure. Make a note on a piece of paper.
- 2). Multiply the length by the width to determine the square footage of the room. Do this by hand or use a calculator.
- 3). Multiply the square footage of the room by 6.5. The result is the amount of wattage that you will need for the room.
- 4). Multiply the wattage by 3.1421 to determine the BTU rate per hour.
- 5). Repeat this process for each room in your home that you want to install a baseboard heater.
- 6). Find a baseboard heater that matches the total wattage and BTU rate for each room.
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