HeatCoolCalc.com provides free HVAC and home energy tools including BTU calculators, AC and furnace sizing, SEER savings calculators, and energy efficiency audit tools. With 28 calculators across 4 categories — from BTU load calculations and heating cost comparisons to insulation R-value guides and ventilation sizing — we cover the tools homeowners actually need, without the clutter.
Our mission is simple: give homeowners accurate, fast, and free HVAC planning tools with no barriers. There are no accounts to create, no paywalls to hit, and no personal data to hand over. You open a calculator, enter your home details, and get your answer. That's it.
Every calculator on HeatCoolCalc uses standard HVAC engineering formulas, Manual J methodology, and established energy efficiency data. We build each tool with care for both accuracy and speed, so the math runs entirely in your browser with instant results.
Whether you're sizing a new AC unit, comparing heating fuel costs, calculating insulation R-values, or figuring out the right ventilation rate for your home, HeatCoolCalc is here to help. We always recommend consulting a licensed HVAC professional for final equipment sizing and installation decisions.
Free, fast, and built for every homeowner.