Disclaimer: *Estimated in good faith, the duct size calculator is meant solely for generic, informative purposes. We do not guarantee the accuracy of this information. Please note that other external factors may affect or falsify the recommendations of this tool. For accurate values, consult a licensed heating and air conditioning professional or building engineer. These calculators and conversion tools are intended solely for general information and educational purposes, and are provided to help inexperienced contractors in the HVAC field and to give more experienced contractors additional reference tools.The calculators and conversion tools provided are not intended in any way as HVAC advice or services, or as a solicitation for any product or service. Any result from use of these calculators and conversion tools may not be applicable or accurate with regard to the individual circumstances, cannot be relied upon for anything, including, without limitation, designs or decisions, and should not be the basis for any action or inaction on your part.