Math & Geometry Tools

Free math and geometry tools that run in your browser — a basic calculator, circle area and circle-from-three-points solvers, 3D surface and complex-function plotters, flashcards for practice, and more. Nothing is uploaded, and there is no account or sign-up.

15 tools available

3D Surface Plotter

Plot z=f(x,y) as a rotatable 3D surface — free, no signup

Circle Area Calculator

Circle area from radius, diameter, or circumference.

Circle From 3 Points Calculator

Circle equation, center & radius from any 3 points.

Basic Calculator

Four-function calculator: correct order of operations, free

Basic Math Flashcards

Endless math flashcards: add, subtract, multiply, divide

Circle Skirt Calculator

Waist radius, hem radius & fabric yardage for circle skirts

Complex Function Plotter

Plot any complex function f(z) as a domain coloring

Conversion Rate Calculator

Sessions and sales in, conversion rate % out.

Cylinder Volume Calculator

Cylinder volume in liters and gallons from width and height

Derivative Calculator

Exact derivative as you type, plus its value at a point

Function Slope Calculator

Tangent line y = mx + b and slope at a point, as you type

Expression Calculator

Type a whole math problem, see the answer as you type

Factor Quadratics Calculator

Factor ax² + bx + c into brackets, with every step shown

Final Grade Calculator

Score you need on the final to reach your target grade

Graphing Calculator

Plot up to 5 functions, Cartesian or polar

Every tool runs in your browser — no upload, no account, free.