Free Tools

Free HVAC Calculators

Professional-grade HVAC sizing tools using real ACCA Manual J constants. Get instant estimates for heating, cooling, and equipment sizing.

BTU Calculator

Calculate heating and cooling BTU requirements for any home.

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AC Tonnage Calculator

Find the right AC size in tons for your home.

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Heat Pump Size Calculator

Size a heat pump with cold-climate derating.

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Furnace Size Calculator

Calculate the right furnace size in BTU/hr.

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Duct Size Calculator

Determine duct sizes for proper airflow.

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Need Permit-Ready HVAC Load Calculations?

These calculators give solid estimates. For exact numbers from your actual blueprints, get a full ACCA Manual J report -- first one is free.

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