A scientific calculator app earns its place the first time a homework problem has a sine, a factorial and three nested brackets in it. Scientific Calculator on Android is one of the free ones people install for exactly that. We built Sigma Pad, a free online scientific calculator that runs right here: no install, no signup, and the answer shows up while you type, so there is no equals key to hunt for.
Use the calculator now
It opens with a parabola already plotted. Type an expression, or tap the keys, and the result updates on every keystroke.
How to use it
Type on a keyboard or tap the keys. The result appears under the expression as you go, and brackets you leave open are closed for you. Press Enter or the = key to save a line to History, where one tap brings it back. The DEG button cycles through degrees, radians and gradians, INV switches sin, cos and tan to their inverses (and log to 10 to the power), and HYP gives the hyperbolic versions. Ans recalls your last answer and M+, M−, MR and MC work the way you expect.
Write powers with ^, factorials with !, and combinations as nCr(5,2). Implicit multiplication works, so 2pi and 3(4+5) are fine. Order of operations is standard: -2^2 is -4 and 2^3^2 is 512.
Type the letter x and a plot of your expression appears. Drag across it, or edit the x field, to move the marker along the curve. The Daily target tab sets one puzzle a day: make the target number from four given digits, using each once. Your streak, history and last expression stay in this browser. Nothing leaves your device.
How it compares to Scientific Calculator
Sigma Pad keeps the part of a scientific calculator people use most: a full expression line, correct precedence, trig in three angle units, logs, powers, roots, factorials and combinatorics. We added two things a typical app does not lead with. The result is a live preview rather than something you wait for, and any expression with x draws itself, which makes a mistyped bracket obvious at a glance.
Answers are rounded to 12 significant digits, so 0.1 + 0.2 shows 0.3 and not a string of floating-point noise. When something cannot be calculated, such as 1/0 or the square root of -1, the message says what to change.
What we left out on purpose: unit converters, themes, widgets, fraction and matrix modes, and anything that needs an account. If you want a calculator on your home screen that opens in one tap, the Android app is the better tool. We also have a plainer online calculator with a running total, and a graphing calculator when the plot is the whole point.
Get the full app
Scientific Calculator is free on Android and lives on your home screen, which a browser tab cannot match for quick checks during the day.
Frequently asked questions
Can I use a scientific calculator online without downloading anything?
Yes. Sigma Pad runs in your browser on a phone, tablet or laptop. Type or tap an expression and the result updates immediately, with no install and no account.
Is this the real Scientific Calculator app?
No. Sigma Pad is an original tool we built, inspired by what a scientific calculator app is for. It is not affiliated with, endorsed by, or connected to the publisher of Scientific Calculator. For the full app, use the store links above.
Does it work in degrees and radians?
Yes. The DEG button cycles through degrees, radians and gradians, and every trig function follows it. Exact angles such as sin(180) in degrees return a clean 0, not a tiny leftover number.
Does it work offline and is it free?
It is completely free. Once the page has loaded it keeps working without a connection, and your history and settings are saved in your browser’s local storage on your device only.
Why does it show an error instead of an answer?
The expression cannot be calculated as written, for example a division by zero, a square root of a negative number, or a bracket with nothing before it. The message under the line explains what to change, and the result returns as soon as you fix it.
