HVAC Load & Sizing Calculator
Not sure what size AC or furnace your home actually needs? Getting HVAC equipment sized right matters. Too small and it can’t keep up on the hottest or coldest days; too big and it cycles on and off constantly, wearing out faster and leaving your home feeling clammy or unevenly heated. Our free HVAC load and sizing calculator gives you a quick, ballpark estimate based on your home’s square footage, ceiling height, insulation, and a few other basics, a helpful starting point before you talk to one of our HVAC contractors about a full, on-site load calculation.
HVAC System Sizing & Load
Residential · 0–5,000 sq ft · Missouri default
| Cooling capacity | 42,000 BTU/hr |
| Heating capacity | 70,000 BTU/hr |
| Suggested furnace size | 80,000 BTU/hr |
| Blower airflow | 1,400 CFM |
Ballpark estimate only, based on simplified rule-of-thumb ratios — not a full Manual J load calculation. Confirm with a licensed contractor before purchasing equipment.
Contact Ashley Brothers Heating & Cooling
Have questions about HVAC equipment load or sizing? Ashley Brothers Heating & Cooling provides dependable residential and commercial heating and cooling services throughout St. Louis, MO. Call 314-835-1770 today to speak with an experienced HVAC contractor about your home’s recommended HVAC sizing requirements or request an estimate.