HVAC Load Calculator
Estimate BTU/hr, cooling tons, and a recommended planning range.
Inputs
Results
How this calculator works
This HVAC load calculator estimates residential cooling capacity for early planning in US units: square feet, BTU per hour, and tons. It helps homeowners compare ballpark system sizes before speaking with a contractor.
Formula and assumptions
The estimate uses a BTU-per-square-foot planning baseline adjusted for climate, insulation, ceiling volume, sun exposure, and occupant heat. One cooling ton equals 12,000 BTU/hr.
FAQ
Is this a Manual J calculation?
No. Manual J is the formal residential load calculation standard. This tool is a planning estimate only.
Why not size only by square footage?
Area alone ignores insulation, windows, air leakage, sun exposure, climate, and occupancy, which can materially change load.
What is one ton of cooling?
In HVAC, one ton of cooling capacity equals 12,000 BTU per hour.
Should I round up to a larger unit?
Not automatically. Oversized equipment can short-cycle and control humidity poorly, so contractor sizing matters.
