HVAC Size Calculator
An oversized AC unit short-cycles and wastes energy. An undersized one never keeps up. Enter your home's details and we'll calculate the right BTU capacity for your space.
How to use this calculator
- Square footage is only the starting point — ceiling height, insulation, and sun exposure matter just as much.
- Get a Manual J load calculation from a pro before installing a whole-home system.
- Replace filters every 1–3 months to keep airflow and efficiency at design specs.
- A programmable or smart thermostat typically pays for itself within a year.
Common mistakes to avoid
- →Forgetting waste and overage. Most pros add 10–15% extra to cover offcuts, mistakes, and damaged material.
- →Measuring once. Always double-check critical dimensions before ordering — returns waste time and money.
- →Ignoring permits and codes. Check with your local building department before purchasing materials for any structural project.
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