- Can I type an expression instead of tapping keys?
- Yes. The line at the top is a real text box: type sin(30)+2^3, paste an expression, move the cursor with the arrow keys and edit in the middle. The keys insert at the cursor. Enter evaluates and Escape clears, and only while the expression line has focus, so Enter still follows links elsewhere on the page.
- Which functions does the scientific calculator support?
- Trigonometry (sin, cos, tan and asin, acos, atan, atan2), hyperbolic functions (sinh, cosh, tanh and their inverses), natural, base-10, base-2 and any-base logarithms (ln, log, log2, logb(x,b) or log(x,b)), exp, square and cube roots and the n-th root root(x,n), powers, factorial (also for non-whole numbers through the gamma function, so 3.5! works), gamma, nPr and nCr, abs, floor, ceil, round, sign, and the constants π, e, φ and τ. Names can be typed in capitals or lower case.
- What does the % key do?
- After a number it is a percentage the way a handheld calculator does it: 50+10% is 55 (ten percent of 50 is added), 200−10% is 180, and 10% alone is 0.1. Between two values it is the remainder, so 10%3 is 1; the mod key does the same (and gives a positive answer for a negative number: −1 mod 5 is 4).
- What is the difference between degree, radian and grad mode?
- Trigonometric functions read their input as degrees, radians or grads (400 to a full turn). In degree mode sin(90) is 1; in radian mode you would write sin(π/2). The inverse functions answer in the same unit. Results that are zero to within rounding are shown as 0, so sin(180°) is 0 and not 1.2e-16.
- What order of operations does it follow?
- Standard mathematical precedence: factorials and powers first (^ is right-associative, so 2^3^2 is 2^9), then multiplication, division and remainder, then addition and subtraction. A leading minus is applied after the power, so -2^2 is -4 — type (-2)^2 if you want 4. Brackets you leave open are closed for you, so sin(30 evaluates as sin(30).
- How are very large and very small numbers shown?
- Auto shows up to 12 significant digits and switches to scientific notation (like 7.257415615 × 10³⁰⁶ for 170!) for very large or small values, so there are no made-up digits. Choose Fixed decimals, Scientific or Engineering and the number of digits under the display, and the same setting applies to history.
- Is there memory, a last answer and history?
- Yes. M+ and M− add or subtract the current value to a memory register, MR puts it in as a value (so 3 then MR is 3×memory, not 37), MC clears it, and Ans is your last result. After = an operator continues from Ans, so a result of −3 followed by x² gives 9. The last 30 calculations are kept in this browser: tap an expression to use it again, or a result to insert it.
- Are the error messages specific?
- Yes. Dividing by zero, a logarithm of 0 or less, a square root of a negative number, asin of a number above 1, a factorial of a negative number, tan at 90°, and a result too large to hold each get their own message instead of a general one.
- Is my data stored or uploaded anywhere?
- No. Every calculation runs locally in your browser using a safe expression evaluator — there is no eval, no server round-trip, and nothing is uploaded. Your last expression, settings, memory and history are saved only to this browser's local storage. The Link button puts your expression after the # of the address, which browsers never send to a server.
- Is the scientific calculator really free?
- Yes — nothing to pay, nothing to register for, no watermark.
- Do I need to create an account?
- No. There's no account system at all. Open the page and start calculating.