About Quemist

Quemist is a chemistry reference site. Calculators for the arithmetic you keep redoing (molar mass, pH, dilutions, gas laws, stoichiometry), unit converters for the awkward chemistry units, and reference pages for the 118 elements and the few hundred compounds that show up most often in coursework and the lab.

Every calculator shows its work. Atomic masses follow the IUPAC standard atomic weights, and the calculation logic has been checked against textbook problems and unit tests. Reference tables cite their sources where it matters (NIST, IUPAC, CRC).

How calculations are handled

Everything runs in your browser. The page loads, the calculator hydrates, you type, and the arithmetic happens locally — no input is sent anywhere. That also means you can share a result by sharing the URL, since the inputs round-trip through the query string.

Quemist is built for learning and reference, not for safety-critical decisions. Verify anything you'd actually act on against a primary source. The Terms of Service spells this out in more detail.

Why it's free

The site is supported by ads. There are no accounts, no paywalls, and no email gates. If you want the details on what the analytics and ad scripts collect, the Privacy Policy covers it.