About this calculator

This site puts the functions of a student scientific calculator in your browser, free. Fractions and roots are displayed as in a textbook, and answers come out exact first, like √2/2, 1/3 or 2π. There are no accounts, and what you type is never sent to a server.

Who makes it

It is made and run by Lumen Lab, a one-person software studio that also makes Daycount, a date calculator, and Owlight, a Mac menu bar app.

How it calculates

• Exact values: fractions are kept as big-integer fractions and roots and π as symbols, so there is no rounding error. When an exact form is not possible it switches to double-precision decimals.
• Order of operations: brackets → functions → powers (left to right) → products without a × sign → × ÷ → + −. So 6÷2(1+2) = 1 and −2² = −4.
• Display: normal display shows 10 significant digits and switches to scientific notation at 10¹⁰ and above or below 10⁻⁹. Rounding is half up.
• Calculus: integrals use adaptive Gauss–Kronrod (7-15) quadrature; derivatives use Ridders’ method.
• Statistics: quartiles use the scientific calculator method by default, with Excel’s QUARTILE.INC as an option.
• Physical constants: CODATA 2022 recommended values from NIST.

How results are checked

Automated tests compare the calculator with about 3,700 answers computed separately in Python (sympy, mpmath, scipy and numpy). The constants were compared digit by digit with the NIST table. Still, double-check important results before using them for exams or work.

Advertising

Google AdSense ads cover the running costs. See the privacy policy for ads and cookies.

Contact

Found a wrong result or missing a feature? Email woxocoso@gmail.com.