About Had2Know.com

Had2Know.com delivers information and online calculators for a wide variety of applications – finance, science, home & garden, mathematics, health & fitness, games, and much more. Is there something you just had to know? We hope we have what you're looking for. Put our extensive collection of online calculators to use, or browse our expertly written articles and how-to guides.

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About Our Authors

Our writers and editors hold a combined 17 degrees and certifications, and over 180 years of experience in their areas of expertise. All of the tools in our Online Calculator Index were developed by our team.

Managing Editor & Co-Founder: Samuel Pearl