Free HVAC Calculators & Sizing Tools
Interactive calculators and sizing guides for air conditioners, furnaces, heat pumps, water heaters, and energy costs
Interactive tools
Instant results
100% free
Standard sizing methods
All HVAC Calculators
AC & Cooling Calculators
Size air conditioners, mini splits, and portable units
Popular
AC BTU Calculator
Calculate the BTUs needed for your room or house
Use calculator
Popular
AC Tonnage Calculator
Convert BTUs to tons and size central AC systems
Use calculator
Mini Split Sizing Calculator
Size ductless mini split systems for multiple zones
Use calculator
Heat Pump Size Calculator
Size heat pumps for heating and cooling
Use calculator
Heating & Furnace Calculators
Size furnaces, boilers, and heating systems
Energy & Cost Calculators
Calculate energy costs, savings, and efficiency
Electrical & Power Tools
Size generators, calculate power consumption
Need Help Choosing the Right Calculator?
Our buying guides and how-to articles provide step-by-step guidance for sizing and selecting HVAC equipment.