Manual J Load Calculator

Simplified heating and cooling load estimate for residential systems based on conditioned area, climate zone, insulation level, and window percentage.

Manual J Load Calculator

Simplified heating and cooling load estimate. Not a substitute for a full ACCA Manual J calculation.

Simplified estimate only

This tool provides a rough BTU estimate using simplified Manual J methodology. A full ACCA Manual J calculation by a certified HVAC contractor is required for proper equipment sizing. Do not use this for equipment selection without professional verification.

Conditioned floor area (sq ft)

IECC climate zone

Insulation level

Window area (% of floor area)

Ceiling height

Cooling Load76,500BTU/hr

= approximately 6.4 cooling tons

Heating Load45,000BTU/hr

= approximately 3.8 heating tons

Manual J Load Calculator

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