Project cost
HVAC Replacement Cost Calculator
Build a planning range for equipment, labor, permits, and project complexity.
Open calculator →Decision tools
Free HVAC calculators with the assumptions left in.
Build a planning baseline, test scenarios, and ask better questions before you commit to a system or contractor.
System sizing
Air Conditioner BTU Calculator
Estimate a preliminary cooling load from area, ceiling height, climate, insulation, and sun exposure.
Open calculator →System sizing
Furnace Size Calculator
Estimate a preliminary furnace output and input rating for a U.S. climate zone.
Open calculator →System sizing
Heat Pump Size Calculator
Estimate nominal heat-pump tonnage and flag when cold-climate verification matters.
Open calculator →Operating cost
Heat Pump vs. Gas Cost Calculator
Compare annual heating cost using your utility rates, heat demand, COP, and furnace efficiency.
Open calculator →Efficiency
SEER2 Savings Calculator
Estimate cooling-energy savings when moving from an older efficiency to a newer SEER2 rating.
Open calculator →System sizing
Mini-Split Size Calculator
Estimate total ductless capacity and a first-pass allocation across indoor zones.
Open calculator →Operating cost
Window AC Running Cost Calculator
Convert watts, daily runtime, and electricity price into monthly and seasonal cost.
Open calculator →Efficiency
Thermostat Savings Calculator
Translate a realistic heating-and-cooling reduction into annual dollar savings and payback.
Open calculator →Airflow
Duct Airflow CFM Calculator
Estimate target system airflow from nominal tonnage and an adjustable CFM-per-ton assumption.
Open calculator →Ownership cost
HVAC Maintenance Budget Calculator
Build an annual reserve for service visits, filters, and unexpected repairs.
Open calculator →Home envelope
Insulation Payback Calculator
Estimate simple payback from project cost, HVAC energy share, and expected load reduction.
Open calculator →