How this calculator works
This tool is designed for early-stage homeowner planning. It uses transparent national 2026 cost benchmarks or engineering relationships where appropriate, then applies the inputs you provide. It is not a contractor bid, an equipment selection, or a substitute for an on-site professional assessment.
Important: HVAC sizing is more complex than square footage alone. ACCA Manual J is the recognized residential load-calculation standard. Use our sizing result only as a planning check, not as final equipment sizing.
What can change the result?
- Local labor rates, permits and inspection requirements
- Equipment brand, capacity, efficiency and matched-system requirements
- Electrical service, gas work, refrigerant line work and condensate drainage
- Duct condition, return-air design, access and installation complexity
- Home envelope, climate and actual heating/cooling load
Use the result well
Use the range to prepare questions, compare quotes and spot missing scope. A professional quote should identify model numbers, efficiency ratings, permit responsibilities, labor warranty, equipment warranty, ductwork or electrical changes, removal/disposal and commissioning.