Hammer CalculatorHVAC
7 of 7 calculators are live. Everything else below is on the roadmap — check back as more launch.
Size heating, cooling, and ventilation equipment based on square footage, climate, and building characteristics. Properly sized HVAC systems run more efficiently, last longer, and keep every room comfortable — these calculators replace guesswork with data.
Quick Tips
- An oversized AC short-cycles, wastes energy, and fails to dehumidify — bigger is not better for HVAC.
- A Manual J load calculation is the gold standard for sizing residential HVAC; use it before buying equipment.
- Seal all duct joints with mastic or foil tape (never cloth duct tape) — leaky ducts can waste 20–30% of conditioned air.