BTU Calculator
Calculate precise heating and cooling requirements for optimal HVAC system sizing
Project Specifications
Floor plan shape
Ceiling profile
Approximate US zone. Lookup tools: energy.gov "ASHRAE climate zone map".
Kitchens get an appliance-heat surcharge.
Knocks ~10% off the cooling load.
DIYRuler estimate
BTU Calculator
Generated
May 17, 2026
Cooling & Heating Requirements
Enter your room size and climate.
We'll size your cooling and heating load and recommend equipment capacity.
- BTU per hour and AC tonnage
- Window-unit, central-AC, and heat-pump suggestions
- Adjusts for climate, insulation, and occupancy