About ManyTools

ManyTools is a growing library of free online calculators and converters. Every tool is free to use, needs no account or sign-up, and runs entirely in your browser. The numbers you type into a calculator are processed on your own device and are not sent to or stored on our servers.

Who operates ManyTools

ManyTools is built and operated by D.J. Gelner through Orion's Comet LLC (Missouri, USA). D.J. Gelner is a former attorney whose practice included antitrust, environmental, and real estate matters. He has spent more than 12 years in business leading negotiations and transactions, and works in marketing. He builds each ManyTools calculator on published, standard formulas and reviews it for accuracy before it goes live.

Our commitment to accuracy

Each calculator is built on well-documented, standard formulas rather than guesswork. Before a tool is published, its math is checked against worked examples and, where relevant, against authoritative references such as the Consumer Financial Protection Bureau and the IRS. We explain exactly how each calculator computes its results, with sources, on our Methodology page.

Our calculators produce estimates for informational and educational purposes. They are not financial, tax, investment, or legal advice, and results depend on the inputs you provide. For decisions that matter, confirm the figures with a qualified professional. The full terms are on our Terms page.

How the tools are built

Behind the scenes, each tool is a shared computational engine paired with a configuration file that supplies the inputs, labels, and copy. A loan engine, for example, powers the mortgage, auto, student, and personal loan calculators using the same vetted amortization math. This keeps the underlying calculations consistent and reviewed in one place as the library grows.

Contact

Questions, corrections, or suggestions are welcome at hello@getorionscomet.com. If you believe a calculator is wrong, please tell us so we can review and fix it.