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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?

Federal efficiency minimums use SEER2, and they depend on the region and on whether the equipment is an air conditioner or a heat pump. SEER 16 is not a federal minimum. A higher SEER2 rating costs more up front and can lower cooling bills where the system runs many hours. Confirm the current Department of Energy minimum for the job before you buy equipment.