HVAC System Types: Split, Packaged, Ductless
Split, packaged, and ductless mini-split HVAC systems compared on thermodynamics, static pressure losses, and efficiency ranges.
Read the guide →HVAC Size Calculator
Calculate the right BTU capacity and tonnage for heating and cooling your home.
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How This Calculator Works
This Preliminary HVAC size estimator estimates the cooling capacity (in BTUs and tons) needed to heat and cool a room or whole house based on square footage, insulation, windows, and climate.
How it works:
- Base load: Square footage × climate zone factor (roughly 22-40 BTU/sq ft depending on climate, from cold to very hot).
- Adjustments: Poor insulation adds 10-20%. Ceiling height over 8 ft adds 4% per additional foot. This is a rough planning estimate — a full Manual J load calculation should be performed before purchasing equipment.
- Tonnage: 1 ton = 12,000 BTU/hr. A Manual J load calculation is the only accurate method for sizing, but this calculator gives a rough estimate you can verify against your contractor's numbers.
Example: A 2,000-sq-ft home in the Midwest with average insulation needs roughly 40,000-48,000 BTU (approximately 3.5-4 tons). The same home in Phoenix needs 60,000+ BTU (5 tons). See our SEER2 ratings guide for efficiency comparisons.
Helpful HVAC Size Calculator Resources
SEER2 Ratings Explained
SEER vs SEER2 testing standards, the M1 static pressure change, Annual Energy Consumption formulas, and regional minimum efficiency requirements.
Read the guide →HVAC Maintenance Schedule by Season
Seasonal HVAC maintenance: capacitor microfarad diagnostics, condenser coil cleaning physics, Delta-T air temperature checks, and combustion safety.
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