About HVAC Calculator

Who this site is for

HVAC Calculator is built for working HVAC contractors and the people around them: technicians checking charge and airflow in the field, contractors pricing replacements, facility managers running small commercial sites, and homeowners who want to understand what their contractor is telling them.

Why it exists

HVAC work runs on numbers that are easy to get slightly wrong: tonnage for the house, CFM for the duct run, superheat on the gauges, payback on the high-SEER quote, or the outdoor temperature where gas beats the heat pump. Small errors compound into short cycling, noisy ducts, failed inspections, oversized quotes, or lost savings. This site exists to make those numbers checkable in minutes, with every assumption visible on the page.

What you will find here

• Calculators with visible math: every input, formula, and output is shown, so a result can be verified by hand or against code tables.
• Reference charts and rate baselines: national averages and typical values, always dated, always labeled as starting points rather than local facts.
• Practical guides: worked examples that pair a parameter table with a hand calculation you can reproduce, written so an apprentice can follow and a journeyman can skim.
• A private Workspace: save assumptions and reports for jobs, quotes, and comparisons without exposing client data.

How content is produced and reviewed

Each calculator ships with machine-checked test cases: fixed inputs must reproduce fixed outputs before the tool is published. Rate baselines carry a data year and are reviewed annually against U.S. Energy Information Administration figures. Guides cite their sources and show the full arithmetic of every worked example. When a reader reports an error through Contact, the page is corrected and the correction is noted.

What this site is not

HVAC Calculator is a planning and reference tool. It is not a substitute for ACCA Manual J, Manual D, or Manual S procedures, the authority having jurisdiction, manufacturer instructions, or the judgment of a licensed HVAC contractor on site. A calculator output is not an approval, a permit, a quote, or a guarantee of performance. Read the Disclosure before relying on any result.

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