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HVAC load calculator.

BTU cooling and heating load, system tonnage, SEER recommendation, and installed price range - simplified Manual J math for planning and budgeting.

Your estimate1800 sqft · mixed climate
40.5k
BTU cooling
40.5k
BTU heating
3.5
Tons
SEER 16+
Recommended
System installed$11,200 - $19,250
Typical installed total$11,200 - $19,250
Equipment only$6,160 - $11,550
Est. annual cooling cost~$1,246
Est. annual heating cost~$1,661

Simplified load estimate for planning. Accurate Manual J requires window area, orientation, local design temperatures, and duct layout. Contractor confirms with a full load calc.

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Common questions

How many BTUs do I need per square foot?

A rough rule is 20 BTU per sqft for cooling in a mixed climate, 25 in a hot climate, and 15 in a cold climate - then adjusted for ceiling height, insulation, and window area. A well-insulated home can need 20-30% fewer BTUs than a drafty one.

How much does a new HVAC system cost in 2026?

A 3-ton central split system installed runs $9,600-$16,500 for an average home. Mini-splits for the same space run $8,400-$15,000. Heat pumps command a premium but lower operating costs. Labor typically equals 40-45% of the total.

What SEER rating should I choose?

SEER 16 is the federal minimum in most regions. SEER 18+ makes sense in hot climates where cooling runs 2,000+ hours/year. In cold climates the payback period on high-SEER equipment is 12-15 years, often not worth the premium.