Scientific Calculator
A full standard and scientific calculator, right in your browser. Build an expression with the buttons below, including parentheses and scientific functions, and press "=" to evaluate it.
How to Use the Scientific Calculator
- Click the number and operator buttons to build your expression — it appears live on the display screen.
- Click "Scientific" to reveal sin, cos, tan, log, ln, √, powers, π, e, 1/x and % functions.
- Use the DEG/RAD toggle (visible in Scientific mode) to choose whether sin, cos and tan treat angles as degrees or radians.
- Press "=" to evaluate the full expression, "⌫" to delete the last character, or "C" to clear everything.
- You can also type directly on your keyboard — digits, + − × ÷, parentheses, Enter for "=", Backspace and Escape all work.
Why Use This Tool?
How does this calculator evaluate expressions safely?
Instead of using JavaScript's eval() (which can be a security risk with untrusted input), this calculator is built with a hand-written recursive-descent parser. Your expression is broken into tokens (numbers, operators, functions, parentheses), then parsed following standard mathematical order of operations — parentheses and functions first, then powers, then multiplication/division, then addition/subtraction — and evaluated purely with safe arithmetic.
Does it respect order of operations (PEMDAS)?
Yes. Multiplication and division are always evaluated before addition and subtraction, exponents bind tighter than both, and anything inside parentheses or a function call is fully resolved first. If you forget a closing parenthesis, the calculator automatically adds the missing one when you press "=" so your calculation still completes.
What's the difference between Degrees and Radians mode?
Trigonometric functions (sin, cos, tan) can interpret angle inputs two ways: Degrees (a full circle = 360, the everyday unit most people learn in school) or Radians (a full circle = 2π, the unit calculus and physics typically use). This calculator defaults to Degrees — toggle to RAD if your formula expects radians.
Is my calculation data stored anywhere?
No. Every calculation happens instantly and entirely inside your browser using JavaScript. Nothing you type is ever transmitted to a server, logged, or saved.