Scientific Calculator — Free Online Scientific Calculator

A complete fx-991-class scientific calculator — two-line display, SHIFT & ALPHA key layers, fractions, trig & hyperbolic functions, powers & roots, nPr/nCr, variables & memory, DMS and a calculation history.

The Scientific Calculator is part of Toolio's Calculators collection — one of 64 free tools on the site. It is made for students, creators, office workers and anyone who needs a reliable scientific calculator without installing software or creating an account. It works on phones, tablets and computers, right in the browser.

How to use the Scientific Calculator

  1. Work it like a real fx-991: amber labels above the keys work with SHIFT, red labels with ALPHA. The top line shows your expression, the line below shows the live answer.
  2. Press MODE to switch DEG / RAD / GRAD. Fractions go in with a b/c (SHIFT + a b/c for mixed fractions) and exact answers stay as fractions — S⇔D flips any answer between fraction and decimal.
  3. Store values with STO (SHIFT + RCL) into A, B, C, D, X, Y or M, add to memory with M+, and tap any entry in the history to reuse it. The display stays locked so your phone keyboard never pops up — tap ⌨ Keyboard only when you want to type.

Scientific Calculator — Frequently Asked Questions

Is this Scientific Calculator free?

Yes — completely free. No sign-up, no account, no installation and no usage fees. Open the page and use it as much as you like.

Do my files leave my device?

No. This tool runs entirely in your browser using JavaScript — your files and text are processed on your own device and are never uploaded to a server.

Does it work on mobile?

Yes. Toolio is built mobile-first, so the Scientific Calculator works in any modern phone browser — Android and iPhone — as well as on tablets and desktop computers, with nothing to install.

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