Area & Perimeter Calculator

Calculate area and perimeter for common 2D shapes with diagrams, formulas, substitution, and worked steps.

GEOMETRY

LOCAL NO DATA SENT

GEOMETRY WORKBENCHAREA / PERIMETER / DIAGRAM / FORMULA / SHOW THE WORK

SHAPECHOOSE A 2D FIGURE

SHAPE TYPE

DIAGRAMSQUARE

Area = s² • Perimeter = 4s

Use any consistent unit. Area will be reported in square units and perimeter/circumference in regular units.

ANSWER ENTER DIMENSIONS The formula is shown before values are substituted so you can follow the same method on paper.

AREA—

PERIMETER / CIRCUMFERENCE—

AREA UNITUNITS²

BOUNDARY UNITUNITS

STEPSFORMULA → SUBSTITUTION → ANSWER

READYChoose a shape and enter its dimensions.

LOCAL TOOL: Shape dimensions and calculations stay entirely in your browser.

FIELD NOTE / 031

Start with the formula before plugging in numbers.

Area measures the space inside a shape, so its answer uses square units. Perimeter measures the distance around a polygon, while a circle uses circumference for that boundary distance. The diagram and substitution steps are meant to reinforce which measurements belong in each formula.

Start with the formula before plugging in numbers.

More tools on the bench