heater grate

Heat BTU Calculator

British Thermal Units (BTUs) are a measurement of energy required to increase temperature, frequently used when discussing heaters. BTUs are defined as the amount of energy required to raise the temperature of one pound of water by one degree Fahrenheit. Now, heater manufacturers use BTUs to make it easier to compare heaters with different capacities and designs. In general, the larger the number of BTUs, the higher the capacity of the heater. For example, a 1,000-BTU heater will use more energy than a 200-BTU. Use the following calculator to understand how many BTUs are needed to heat your indoor space.

Learn more about BTUs and other HVAC terms in our HVAC Glossary.

Heating BTUs

Enter information about your space to calculate the amount of British Thermal Units (BTUs) required to properly heat it.

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Your area requires {{ calcFinal }} BTUs to heat properly.

If you live in North America, use the map below to choose the appropriate climate zone number.

climate zone map of North America

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