Enter your space details and get an accurate BTU load and tonnage recommendation — no HVAC license required.
Educational estimate only. Results are estimates based on user inputs and simplified assumptions — not a certified engineering analysis. Local building codes and manufacturer specifications govern final equipment selection. No professional-client relationship is created by using this tool. For permit applications, commercial projects, or complex structures, consult a licensed HVAC engineer.
HVAC Tool Suite
Start with your load result, then move into airflow, duct sizing, and comfort checks. Each tool is designed for fast residential planning with simple inputs and immediate outputs.
Estimate BTU load and recommended tonnage for a room or whole home.
Turn heating or cooling load into estimated airflow needed per room or zone.
Convert airflow into approximate duct sizes using a simple equal-friction approach.
Enter dry bulb and relative humidity to read key comfort and air-state values.
Open toolConvert cooling capacity fast for quotes, comparisons, and sanity checks.
Open toolUnderstand the basics of airflow resistance and what it means for system performance.
Open toolEstimate air changes per hour and compare ventilation needs across spaces.
Open toolA BTU (British Thermal Unit) is the energy needed to raise 1 lb of water by 1°F. HVAC systems are rated in BTU/hr — the higher your load, the larger your system needs to be.
One "ton" of cooling equals 12,000 BTU/hr. It comes from the heat absorbed by melting 1 ton of ice per day. Residential systems typically range from 1 to 5 tons.
An oversized system short-cycles — it cools too fast, shuts off, and never runs long enough to dehumidify properly. This leads to a clammy, uncomfortable home and higher wear on the equipment.
Quick Answers
Everything homeowners and contractors ask most — answered in plain English.