Scientific Calculator

How the Scientific Calculator Works

The Scientific Calculator lets you type a complete math expression—using numbers, operators, parentheses, trig, logarithms, roots, and powers—and evaluates it in one step. It uses a dedicated parser to tokenize your input, converts it to reverse Polish notation (RPN), and then evaluates that RPN with a safe internal math engine that follows standard precedence rules and your chosen angle mode.

Expression-Based Input with Parentheses

Instead of computing each operation one at a time, you can write expressions the way they appear in textbooks:

• Combine multiple operations in one line, like 3 + 5 × 2.
• Use parentheses to group parts of the expression, such as (1 + 2) × (3 + 4).
• Mix functions and constants, such as sin(30) + ln(2) or 2π × 3.

The calculator automatically handles implicit multiplication in common patterns, like 2π or 3sin(45), by inserting the necessary multiplication step internally.

Trig, Inverse Trig & Angle Modes

Trigonometric functions are sensitive to angle units, so the calculator provides a Rad/Deg toggle:

• In Rad mode, inputs to sin, cos, tan are interpreted in radians, and inverse trig outputs are returned in radians.
• In Deg mode, inputs are interpreted as degrees, and inverse trig outputs are returned in degrees.
• The Inv toggle switches the trig keys between sin/cos/tan and asin/acos/atan without changing the layout.

This makes the calculator flexible enough for geometry, trigonometry, and calculus-style problems that require precise control over angle units.

Logs, Roots, Powers, Factorial & Percent

The calculator also covers core scientific operations:

• ln computes natural logarithms (base e), and log computes log base 10, with domain checks so non-positive inputs return a math error.
• √ takes square roots and blocks negative inputs in the real-number setting.
• xʸ raises one value to the power of another.
• x! evaluates factorial for integers ≥ 0 up to a safe limit to avoid overflow.
• % is a postfix operator that converts the preceding value into a percentage by dividing it by 100.
• EXP helps you enter scientific notation, so 3.2 EXP 5 becomes 3.2 × 10⁵.

Error Handling & Safe Evaluation

The calculator is designed to fail safely. If you type an expression the engine cannot interpret—such as mismatched parentheses or an incomplete function call—it shows “Syntax Error” without crashing. If the math itself is invalid—like a factorial of a non-integer or a logarithm of a negative—it shows “Math Error.” In both cases, you can adjust the expression and press = again without reloading the page.

What This Scientific Calculator Doesn't Do

To stay fast and easy to use, this Scientific Calculator intentionally avoids some advanced features:

• No equation solver or symbolic algebra system.
• No graphing, matrices, vectors, or complex numbers.
• No memory registers (M+, M−, MR, MC); only a simple Ans key for the last result.

It focuses on the core scientific functions students and everyday users need most—trig, logs, powers, roots, factorial, percent, and constants—in a single, browser-based calculator that's mobile-friendly and SEO-optimized.