WhatIs.site Free Tools
Useful, no-signup tools that pair with our explainers. All calculations happen in your browser — your data never touches our servers. Bookmarkable, printable, sharable.
Compound Interest Calculator
Calculate future value with monthly contributions, multiple compounding frequencies, and a year-by-year breakdown.
Word Count & Reading Time Calculator
Count words, characters, and sentences. Estimate reading time at any WPM. Plus Flesch-Kincaid grade level.
Unit Converter
Convert length, mass, volume, temperature, area, time, speed, energy, pressure, and data storage units instantly.
Why these are free
We make explainers. Tools are an extension of that — they let you actually use the concepts we write about. Our compound interest calculator pairs with our compound interest explainer; the unit converter pairs with our science and engineering categories.
No ads on the tool pages. No tracking pixels. No signup walls. Just useful calculators that work.
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