Free HVAC Sizing Calculator. Calculates BTU/kW/HP/Ton based on floor area, ceiling height, climate zone, insulation, and window exposure. Includes unit type recommendations. · Pure Frontend · No Server Uploads
Zero Dependencies·Works OfflineCapacity is commonly measured in BTU/h or Tons. Selection depends on room area, ceiling height, insulation, window exposure, and climate. This calculator provides a scientific estimate; consult a professional HVAC engineer for final sizing.
Heating typically requires 10-20% more capacity than cooling due to larger indoor-outdoor temperature differences in winter. Heat pump efficiency drops in cold weather — consider low-temperature heat pump models in cold regions.
Oversized: frequent cycling, poor humidity control, high energy bills. Undersized: runs continuously without reaching temperature, compressor overwork, shorter lifespan. Correct sizing can save 20-30% energy.