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Cooling Load Calculators

Choosing the right size air conditioner is critical for your comfort and energy efficiency. An oversized unit will short-cycle and fail to remove humidity, while an undersized unit will run constantly and struggle to keep you cool. Use our free tools below to find the perfect fit.

AC Tonnage Calculator

Our comprehensive tool for calculating the cooling load and tonnage required for your home based on square footage, climate, and insulation.

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Portable AC Size Calculator

Determine the correct BTU rating for a portable air conditioner. Perfect for single rooms, apartments, or supplemental cooling.

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Mobile Home AC Size Calculator

Specialized sizing for manufactured and mobile homes, accounting for different insulation standards and construction types.

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Why Use an AC Sizing Calculator?

When it comes to air conditioning, bigger isn't always better. The process of determining the correct AC capacity—measured in BTUs or tons—is called a cooling load calculation.

HVAC professionals use complex manuals (like ACCA Manual J) to perform these calculations, but our tools provide a highly accurate estimate by accounting for essential variables like your local climate zone, home square footage, ceiling height, and insulation quality.

The Dangers of Improper Sizing

  • Oversized AC Units: Cool the house too quickly and shut off before they have a chance to remove humidity from the air, leaving your home feeling clammy and cold. This "short-cycling" also damages the compressor over time.
  • Undersized AC Units: Run non-stop during hot days, driving up your energy bills and wearing out parts prematurely without ever reaching your target thermostat temperature.

Select the calculator above that best matches your needs to get a reliable estimate before you purchase new equipment or request quotes from contractors.