Utility · Mobile-first

HVAC residential load estimator (rule-of-thumb)

Enter conditioned square feet and pick a broad U.S. climate band — see implied cooling tons and a BTU/h order-of-magnitude. Teaching sketch for trucks and sales; not ACCA Manual J or stamped engineering.

Runs in your browserNo signup

HVAC residential load estimator (rule-of-thumb)

Not Manual J. This is a coarse classroom sketch using generic sqft-per-ton bands. Real loads need block-by-block heat gain, insulation, windows, ducts and local code — hire a licensed designer before ordering equipment.
Implied cooling tons (rough)3.27 tons
Cooling capacity order-of-magnitude39,273 BTU/h
Heating sanity multiple (not fuel-specific)41,236 BTU/h

Based on 1,800 sq ft ÷ 550 sq ft/ton × 12,000 BTU/h per ton. Use for whiteboard talk only.

Key takeaways

  • Order-of-magnitude tons from sq ft and a climate pick.
  • Explicitly not Manual J — avoids false precision.
  • Useful before calling a designer or comparing quotes.
  • Pairs with our HVAC software comparisons after you know ballpark size.
  • Runs locally; nothing uploaded.

Who built this

ContractorHQ is edited by Bernard Guido — 25+ years in trade operations and software. These utilities follow the same quality bar as our reviews: fast pages, honest disclosure, and tools that stay useful without selling your data.

Frequently asked questions

Is this Manual J?

No. Manual J requires detailed window, wall, infiltration and duct inputs. This page uses generic sqft-per-ton bands only so a crew can sanity-check equipment talk tracks — not size equipment for permits.

Why three climate bands?

Hot-humid or high-sun areas often need more cooling per square foot than mild or heating-dominant regions. The bands are still crude; local design still wins.

Does this include latent load or ventilation?

No. Sensible-only order of magnitude. Fresh air, duct leakage and latent loads can swing real tons significantly.

Can I use the heating number for a furnace?

The heating line is a non-fuel-specific multiplier for conversation only. Fuel type, efficiency, envelope and code all change equipment selection.