HVAC Calculators

Free calculators for heating, ventilation, and air conditioning. Size equipment, design ductwork, and verify refrigerant charge.

Calculate BTUs needed to heat or cool a room based on size, insulation, and climate.

Calculate the right AC unit size in tons for your home or room.

Calculate the right duct diameter based on CFM airflow requirements.

Estimate BTU/hr heat loss through walls, windows, and ceilings for furnace sizing.

Calculate superheat and subcooling to verify refrigerant charge levels.