BTU Calculator

HVAC sizing estimate

Results

Recommended capacity
AC tonnage
Room area
Notes

How to use

  • AC BTU — enter room size and ceiling height with units, then set occupancy, room type, insulation, sun exposure, and climate.
  • Heating BTU — enter width, length, and ceiling height, then insulation and the indoor/outdoor temperature difference you need to overcome.
  • Results are rough planning estimates only—not a Manual J load calculation.

Disclaimer. Informational only—not HVAC design, Manual J, or energy-audit advice. Actual loads depend on insulation, windows, ductwork, and local codes; consult a licensed HVAC professional.