HVAC Tonnage Calculator
Quick estimate of AC or heat pump tonnage for residential jobs. This is a Manual J shortcut for fast quoting — not a substitute for a full load calculation on install.
How it works
The rule of thumb HVAC contractors use is roughly 1 ton per 600 sq ft of conditioned space — but that varies significantly by climate zone, insulation quality, sun exposure, ceiling height, and window-to-floor ratio. This calculator applies a simplified multiplier so you can ballpark a sizing range in seconds. Always run a proper Manual J load calc before final install.
Climate zone multipliers (rough): Hot/humid (TX, FL, AZ) increases load ~20%. Cold (MN, ME, ND) reduces cooling load ~15%. Mild (CA coast, PNW) is closest to baseline.
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Once you've quoted the tonnage, ScopeCrafters drafts the full scope, materials list, terms, and warranty with the right SEER2 / AHRI / refrigerant vocabulary. Branded PDF emailed to your customer. $79/mo flat, 7-day free trial.
See HVAC proposal generator