Free HVAC Calculators & Sizing Tools
Interactive calculators and sizing guides for air conditioners, furnaces, heat pumps, water heaters, and energy costs
All HVAC Calculators
AC & Cooling Calculators
Size air conditioners, mini splits, and portable units
AC BTU Calculator
Calculate the BTUs needed for your room or house
AC Tonnage Calculator
Convert BTUs to tons and size central AC systems
Mini Split Sizing Calculator
Size ductless mini split systems for multiple zones
Heat Pump Size Calculator
Size heat pumps for heating and cooling
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
How to Use Our HVAC Calculators
Enter Your Details
Input your room size, home details, or current energy usage
Get Instant Results
Professional calculations based on industry standards
Make Informed Decisions
Use results to size equipment, compare options, and save money
Need Help Choosing the Right Calculator?
Our buying guides and how-to articles provide step-by-step guidance for sizing and selecting HVAC equipment.