About MathKit

MathKit exists because math help online should be fast, calm, and accurate — ads and analytics wait until after your calculation loads, no heavy pages, no guessing whether the formula is right.

We build every calculator the same way: pure, unit-tested math logic, clearly labeled inputs, inline validation, and a worked example you can follow. The site is fully static, so pages open instantly and calculations happen entirely in your browser.

What you'll find here

• Calculators — from percentages to quadratic equations to loan payments.
• Reference tables — multiplication tables, primes, squares, Roman numerals and more.
• Practice — quizzes and printable worksheets that work without a login.
• Guides — short, original explanations of the ideas behind the tools.

Our principles

• Correct math, always — every tool ships with verified test cases.
• No dark patterns — minimal ads (when present), never before the answer.
• Privacy by design — your inputs never leave your device.

How the tools are built

The site now runs 76 calculators, 307 reference-table pages, 8 original guides and four practice modes. Each calculator's logic is a pure, reviewed function covered by a 142-test unit suite that runs on every push (type checks included), and each page ships a worked example showing the method out loud — so the claim you read is the code you get.

There is no backend and no account anywhere. Pages ship as static files, every calculation runs inside your browser, and your inputs never leave the device. That is why answers appear instantly and the site keeps working on a slow connection — the only network traffic is analytics and the minimal ad script, never your math.

How we keep the math honest

A passing formula is not the same as a trustworthy tool, so the test suite deliberately leans on the edge cases: zero and negative sizes, empty inputs, division by zero, non-integer inputs like 97.5 on whole-number fields, over-100% discounts, and dates entered back-to-front. Those inputs now produce a red, plain-language error on the exact field instead of a nonsense answer such as a −16 price or a "-30" day count.

The same discipline applies to the words on the page. Number FAQs are written against the calculator's own engine — "15625 mod 23 = 8" is computed, not guessed — and engine conventions that could confuse, like JavaScript's negative-remainder behavior in the modulo tool or population variance in the statistics tools, are stated in a FAQ rather than left as surprises.

What we will never do

• No sign-up walls — every tool works the moment the page loads.
• No selling or transmitting your inputs — the computations never touch a server.
• Ads wait — placements load after a delay or interaction, never cover the calculator, and never sit between your input and your answer.
• No fake precision — results show what is actually computed, and do not pretend.

Where the site is heading

More topics, deeper guides, and the same bar for anything new: it must compute correctly, load instantly, and explain itself before it counts as finished. If a tool you need is missing, thecontact page takes requests directly — a plain mailto form with no data collection, the same privacy rule the calculators follow.