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Free algebra and graphing tool

Graphing Calculator

Plot mathematical functions on an interactive coordinate plane. Compare up to three equations, inspect coordinates, change the visible window, pan, zoom and download the graph—all directly in your browser.

✓ No sign-up✓ No equation uploads✓ Three function plots✓ Mobile friendly

Function inputs

Enter equations

Enter the expression after y =. Examples: x^2, sin(x) or 2x+3.

Graph window

Coordinate plane
Move over the graph to inspect coordinates
Your browser needs Canvas support to display this graph.
Drag to pan · wheel or buttons to zoomStandard graphing uses radians unless Degrees is selected
Five sample values across the selected x-range
x
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What does the Graphing Calculator do?

This calculator draws functions of one variable on a two-dimensional coordinate plane. Each enabled expression is evaluated across the selected x-range and converted into plotted points. You can compare a quadratic with a line, examine periodic functions, explore powers and roots or see how changing coefficients changes the shape and position of a graph.

The tool is an original browser-based calculator provided by Online Calculator Tools. It is not Desmos and is not affiliated with Desmos Studio. Equation parsing and graph drawing happen locally in the browser rather than being submitted to a calculation server.

Supported graphing syntax

Enter the right-hand side of a function without typing y=. Multiplication can be explicit, as in 2*x, or implicit, as in 2x and 3(x+1).

Arithmetic and powers+, -, *, /, ^ and parentheses
Constantspi, π and e
Trigonometrysin, cos, tan, asin, acos, atan, sec, csc, cot
Other functionssqrt, abs, log, ln, exp, floor, ceil, round, sign
Examples: x^2-4, sin(x), sqrt(abs(x)), log(x) and 2x+3.

How to graph an equation

  1. Enter a function of x in one of the colored expression fields.
  2. Use its checkbox to show or hide that curve.
  3. Choose Radians or Degrees when the expression contains trigonometric functions.
  4. Adjust the minimum and maximum x and y values if you need a different viewing window.
  5. Select Plot Functions. Drag the graph to pan, and use the wheel or zoom buttons to change scale.
  6. Move over the graph to inspect an approximate coordinate. Use the sample table for five evenly spaced evaluations.

When an expression contains an unsupported name, character or unmatched parenthesis, the calculator shows an error directly below that expression and continues drawing any other valid, enabled functions.

How to interpret the graph

An x-intercept is a point where the curve crosses the horizontal axis and the function value is zero. A y-intercept is the value shown where x equals zero. Turning points, repeated patterns and intersections can help you understand the behavior of an equation, but the displayed graph is a numerical rendering rather than a symbolic proof.

Zooming changes the visible scale and can reveal features that are compressed in a wide window. Conversely, a very narrow window can make a curve appear almost straight. When comparing functions, keep the same axes and angle mode. The coordinate readout and sample table are approximations based on browser floating-point arithmetic.

Accuracy and limitations

The plotting engine samples many x-values and connects nearby valid points. It deliberately breaks a line when values become non-finite or jump sharply, helping avoid a false connection across some discontinuities. Very narrow spikes, rapid oscillations or features between sampled positions may still be missed. Functions with restricted domains, such as sqrt(x) or log(x), are shown only where the result is a real finite number.

Use the calculator for learning, exploration and visual checks. For formal coursework, engineering or scientific analysis, confirm important roots, extrema, discontinuities and intersections with algebraic methods or specialized numerical software.

Graphing Calculator FAQs

It plots up to three functions of x using arithmetic, powers, parentheses, constants, trigonometric functions, logarithms, roots and several common mathematical functions.
No. Enter only the expression after y equals, such as x^2, sin(x) or 2x+3.
Yes. Expressions such as 2x, 3(x+1) and x(x-2) are interpreted as multiplication.
Yes. Select Degrees in the angle-mode field when you want trigonometric inputs and inverse-trigonometric outputs expressed in degrees.
Use the zoom buttons or mouse wheel to zoom. Drag the graph with a mouse, pen or finger to move the visible window.
No. Equation parsing and graph drawing run locally in your browser.
A gap can occur where a function is undefined, outside the selected y-range or changes too sharply near a discontinuity.

Sources and methodology

The graph is produced with a purpose-built expression parser and the browser's Canvas drawing surface. These references document mathematical functions and the graphics technology used by the calculator.

NIST Digital Library of Mathematical FunctionsReference material for mathematical functions, notation and properties.WHATWG HTML — Canvas elementTechnical definition of the browser drawing surface used for the graph.

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