Scientific Calculator

How the parser works

The calculator reads your expression, breaks it into tokens (numbers, operators, functions, parentheses, constants), and then evaluates it with a recursive-descent parser that applies precedence in the correct order: parentheses first, then functions and postfix operations like factorial and squaring, then exponents, then multiplication and division, then addition and subtraction. Typing a value directly in front of a function, constant, or opening parenthesis, for example 2π or 3(, automatically inserts a multiplication sign, so you rarely need to type the × key yourself in those cases. Results are rounded to 12 significant digits to avoid floating-point artifacts like 0.1 + 0.2 showing extra trailing digits.

Degrees vs. radians

Use the DEG / RAD toggle above the display to choose how sin, cos, and tan interpret their argument. DEG treats the number as degrees, so sin(30) returns 0.5. RAD treats it as radians, so sin(π÷2) returns 1. Switch the mode before you evaluate a trig expression, since the toggle only affects calculations you run after changing it, not results already on the display.

Function reference

sin, cos, tan compute trigonometric ratios using whichever angle mode is active. log is base-10 logarithm and ln is natural logarithm. √ takes a square root and throws an error on a negative argument, since the calculator only handles real numbers. x² squares the value in front of it, and xʸ raises a base to a power using the caret operator, evaluated right to left so a chain like 2^3^2 computes 2^(3^2). n! computes a factorial for non-negative integers, 1/x takes the reciprocal, and % divides the value by 100. The constants π and e insert their standard mathematical values.

Memory buttons

M+ adds the current value to memory, M− subtracts it, MR recalls the stored value into the expression, and MC clears memory back to zero. The memory value persists across calculations until you clear it or close the tab, so you can build up a running total across several separate expressions.

Tips for accurate results

Watch your DEG/RAD setting before evaluating any expression that includes sin, cos, or tan. Entering an angle in degrees while the calculator is in RAD mode, or the reverse, is the single most common source of a result that looks wrong even though the expression itself is correct. When you're chaining several operations, wrap each stage in parentheses rather than relying purely on precedence, since a parenthesized expression is both easier to read back on the small display and less likely to evaluate in an order you didn't intend. If a calculation returns an error, check first for an unmatched parenthesis, a negative number under a square root, or a factorial applied to something other than a non-negative whole number, since those are the three conditions the parser rejects outright.

Common use cases

Students use this calculator to check trigonometry and logarithm homework without switching between a graphing calculator and a browser tab. Engineers and hobbyists use it for quick unit-free physics or geometry calculations, angles, roots, and exponents, where a phone's built-in calculator app doesn't expose scientific functions without extra taps. The order-of-operations support also makes it useful for checking a multi-step formula in one line rather than computing each piece by hand and combining the results yourself.

Worked examples

Keyboard shortcuts

Number keys, + − * / for operators, ( ) for parentheses, Enter for equals, Backspace to delete, Esc to clear. The keyboard shortcuts stay disabled while you're typing inside another input field on the page, so they won't interfere with anything else you're doing.

Is the Scientific Calculator free?

Does it follow order of operations?

What functions are supported?

How does the DEG / RAD toggle work?

How do the memory buttons work?