Geometry Calculators
Geometry calculators for shapes, lines and angles, with the formula behind each answer explained.
Shapes and solids
- Area CalculatorThe area calculator gives the area of a circle, rectangle, triangle, parallelogram, trapezoid, ellipse or rhombus, with the perimeter and the formula for each.
- Volume CalculatorA volume calculator that does surface area too, with the formula worked through on your numbers. When the measurements are whole numbers, it also gives the answer as a multiple of pi.
- Circle CalculatorGive the circle calculator any one of radius, diameter, circumference or area and it returns the rest, exact in terms of π. It also does arcs, sectors and chords, the equation of a circle both ways, and the circle through three points.
- Triangle CalculatorThe triangle calculator solves from whatever sides and angles you know, including the right-triangle case, which is the Pythagorean theorem and most of the traffic.
- Regular Polygon CalculatorGive the regular polygon calculator the number of sides and one measurement, and it returns every other length, the area and the angles.
- Acreage CalculatorThe acreage calculator turns lot dimensions into acres, square feet, square meters and hectares, for rectangular, triangular, circular and irregular four-sided lots.
Lines and angles
- Slope CalculatorThe slope calculator finds the slope from two points, or a line from a point and a slope, as an exact fraction, with the slope-intercept, point-slope and standard forms, the intercepts and the angle.
- Distance Formula CalculatorThe distance formula is the Pythagorean theorem with the triangle left implicit. This distance formula calculator draws it back in.
- Trigonometry CalculatorA trigonometry calculator for sin, cos and tan, plus csc, sec and cot, with the exact value at the special angles (sin 60° is √3/2) and inverse trig from a value back to every angle that produces it.
- Unit Circle CalculatorThe unit circle calculator gives any angle's point (cos θ, sin θ), its quadrant and reference angle, and all six trig values, in degrees or radians and exactly where they are exact.
More categories
- Math CalculatorsMath calculators that show their work: arithmetic, algebra, statistics, and a calculus calculator for derivatives and integrals, with exact answers in fractions and radicals where they exist.
- Chemistry Calculators, Physics and Lab ToolsChemistry calculators, physics calculators and molecular biology tools for the bench and the problem set.
- Conversion CalculatorsConversion calculators for unit conversion, number bases, Roman numerals and angles. The unit converter shows the factor it used and a conversion chart for the values around yours.
- Date and Time CalculatorsDate and time calculators for counting days, adding hours, converting time zones and reading other calendars.
- Business CalculatorsBusiness calculators for pricing a product and for the unit economics behind a company: margin, markup, break-even, ROI, CAC, LTV and churn.
- Random GeneratorsRandom generators that draw fairly, from your browser's cryptographic generator: numbers, names, teams, coin flips and dice.
- Everyday Cost CalculatorsCost calculators for what a meal, a drive or an appliance actually costs: tips, split bills, fuel, electricity and EV charging.
- Free Online ToolsFree online tools for codes and text, run in your browser with nothing uploaded.