Energy & Utilities

HVAC BTU Calculator

Lets users plan and optimise hvac btu instantly with formula, steps and examples — no manual math.

Enter your details

sq ft
010
Your result
Cooling capacity needed
4,000 BTU/hr

≈ 4,000 BTU/hr → about a 0.25-ton air conditioner.

Recommended AC size
0.25 ton AC
In tons
0.3333 ton

About this calculator

Air-conditioner sizing: ~20 BTU per square foot, +600 BTU per occupant above two, +10% for sunny or kitchen rooms. 12,000 BTU/hr = 1 ton of cooling.

Frequently asked questions

Why CalcBreeze

  • ✔ Verified formulas, instant recalculation
  • ✔ Works on every device, no signup needed
  • ✔ Save, share & export results
  • ✔ 1100+ calculators across 50+ categories
  • ✔ Pixel-consistent design across every tool

Explore more Energy & Utilities calculators