Math Expression Evaluator
Calculate math expressions as you type — sum, subtraction, multiplication, division, powers, square root, log, sin, cos, tan and parentheses. Shows the result. Everything in your browser.
Math Expression Evaluator
A math expression evaluator takes a string like 2 + 3 * sin(pi/4) and gives back a number. Behind the scenes it tokenizes the input and turns the infix notation into a syntax tree, usually with the Shunting-yard algorithm (Dijkstra, 1961) or a recursive-descent parser. The precedence is fixed. Parentheses come first, then the exponent ^, then * /, and finally + −. Exponentiation is right-associative, so 2^3^2 = 2^9 = 512 rather than 64. Functions (sin, cos, log, sqrt) and constants (π, e) are all handled. The variant you find in HP calculators is Reverse Polish Notation (RPN/postfix).
Applications and context
Expression evaluators sit under a lot of everyday software. They run the formulas in spreadsheets (Excel, Google Sheets), the math in computer algebra systems (Wolfram Alpha, SymPy, GeoGebra), the designer-written formulas inside game engines, and plenty of scientific automation. One security note: don't reach for raw eval() in JavaScript, because it will run arbitrary code. A dedicated parser like math.js or mathexpr keeps the evaluation sandboxed.
Calculate math expressions by typing
There are moments when you don't want to keep pressing a calculator button by button. You want to write the whole calculation and see the result. This evaluator reads math expressions written out and respects the order of operations and the parentheses, exactly the way you'd do it on paper.
It doesn't stop at the four operations: it takes powers, roots, logarithms and trigonometric functions (sin, cos, tan), which helps with more elaborate calculations in maths, physics or engineering. And it doesn't show only the answer. The step by step comes along with it, so you can check and understand how the expression was evaluated.
The calculation runs in the browser. Type the full expression and the answer appears. It's a calculator that speaks your language, without you hunting around for keys.
Frequently asked questions
Does it work in radians or degrees?
Why does 0.1 + 0.2 not equal 0.3?
Can I use variables?
Related Tools
Multiplication Table
Generate the multiplication table for any number. See the multiplication line by line up to any multiplier.
Parametric Curves
Animate and plot parametric curves defined by x(t) and y(t). Explore Lissajous, spirals, epicycloids, roses and other classic curves.
Factorial Calculator
Compute n! (factorial) for any integer up to 170 (double precision limit). Above that, returns exact BigInt. Useful for combinatorics, probability and discrete math. Everything in your browser.
Rule of Three Calculator
Solve a simple rule of three online. Enter three values and automatically calculate the fourth.
Function Animation
Visualize and animate mathematical functions f(x, t) in real time. The parameter t varies automatically — perfect for waves, trig functions and dynamic equations.
Fibonacci Sequence Generator
Generate the first N terms of the Fibonacci sequence. Shows the sequence, the nth term and the sum of all terms.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.