About

FigureNook is a free collection of 60 online calculators, unit converters and small utilities for money, health, math, dates, text and code.

Who runs this site

FigureNook is an independent site. Every tool is built and checked by hand before it goes live. It is not affiliated with any bank, lender, insurer or health provider, and no tool on the site is sponsored or tuned to push you towards a product.

Why it exists

Most calculator sites hide the method. They ask for a number and hand back an answer, often surrounded by sign-up prompts. We think you should be able to see how a result is worked out. That is why every page here includes the formula it uses, a worked example you can check by hand, the assumptions behind it and the questions people most often ask about it.

How the tools are built

• Published formulas. We use standard, widely cited methods, such as the amortization formula for loans, the Mifflin-St Jeor equation for metabolic rate and the US Navy method for body fat, and we say so on each page.
• Exact conversion factors. Unit converters use internationally defined values, such as 1 inch = 2.54 cm and 1 pound = 0.45359237 kg.
• Tested. Every calculator is run automatically against its default inputs and every option each time the site is built, and the build fails if any tool errors or returns an invalid number.
• Private. All calculations run in your browser. What you type is never sent to us.

Accuracy and limits

We work hard to get things right, but calculators are only as good as the inputs and assumptions behind them. Financial results are estimates and do not include every fee or local rule. Health results are population-based estimates, not medical advice. Please confirm important decisions with a qualified professional.

Get in touch

Found a mistake, want a new tool, or have a suggestion? Email figurenook@gmail.com or use the Contact page. Corrections are always welcome, and we fix confirmed errors quickly.