calcs.homes

HVAC — heating & cooling calculators

8 free tools for sizing air conditioning, heating, mini-splits, and backup power.

BTU Calculator Most popular
Cooling BTU per hour and AC size from room size and conditions.
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AC Tonnage Calculator
Central AC size in tons and BTU from home size and climate.
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Mini Split Sizing Calculator
BTU load and nearest ductless mini-split head size for a room.
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Furnace Size Calculator
Heating BTU output and input rating from home size and climate.
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Heat Pump Size Calculator
Heat pump tons and BTU, with a rough cold-climate backup figure.
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SEER Savings Calculator
Yearly and 10-year savings from upgrading to a higher-SEER AC.
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Heating BTU Calculator
Garage / shop heater size in BTU and watts by volume and temp rise.
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Generator Sizing Calculator
Continuous and peak watts, and the generator size to buy.
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