Calculate area of any shape instantly
Click on the grid to place each corner of your shape, in order. Once you have at least 3 points, the starting point turns gold — click it again to close the shape, or press "Close Shape & Calculate" below. Drag any point to move it, double-click a point to delete it, or edit a line's length directly in the list below.
Most area calculators handle a handful of basic shapes and stop there. This area calculator covers 18 standard shapes, from squares and circles through trapezoids, annuluses, and L-shapes, plus a Draw Custom mode for any irregular shape you can trace on a grid, all with instant unit conversions.
Each of the 18 standard shapes uses its own specific geometric formula, applied directly to whatever dimensions you provide. Draw Custom works differently: rather than relying on a formula for a fixed shape, it calculates area directly from the coordinates of the points you place on the grid, using the shoelace formula, which works for any simple polygon regardless of how irregular it is.
| Shape | Formula |
|---|---|
| Square | side² |
| Rectangle | length × width |
| Circle | π × radius² |
| Triangle | ½ × base × height |
| Trapezoid | ½ × (base1 + base2) × height |
| Ellipse | π × semi-major axis × semi-minor axis |
| Parallelogram | base × height |
| Rhombus | ½ × diagonal1 × diagonal2 |
| Regular Polygon (Pentagon, Hexagon, Octagon, or N-sided) | ½ × perimeter × apothem |
| Sector | ½ × radius² × angle (radians) |
| Semicircle | ½ × π × radius² |
| Annulus | π × (outer radius² − inner radius²) |
| Segment | Sector area − triangle area formed by the chord |
| L-Shape | Sum of two rectangles making up the L |
When a shape doesn’t match any standard formula, an irregular plot boundary, an oddly shaped room, a custom garden bed, Draw Custom lets you trace it directly. Setting the Grid Scale first (what one grid square equals in your chosen unit) is what makes the resulting area accurate rather than just visually proportional. Once you’ve placed at least 3 points and closed the shape, the calculator computes area from those exact coordinates, no matter how irregular the resulting polygon is. You can drag any point to adjust it, double-click to delete a point, or edit a specific edge’s length directly in the list below the canvas.
Alongside your numeric result, the Formula card shows exactly which equation and values were used to reach it, useful for checking your work or understanding why changing one dimension affects the area the way it does. The Unit Conversions panel then shows that same area expressed in every other supported unit simultaneously, so a result calculated in square feet can be checked in square meters, or vice versa, without re-entering anything.
Use Draw Custom. Set your Grid Scale to match your actual measurements, then trace the boundary point by point on the grid. This calculates area directly from the shape you draw rather than requiring it to match one of the 18 standard geometric formulas.
It uses the shoelace formula, a standard method that calculates a polygon’s area directly from the coordinates of its corners, in the order they were placed. This works for any simple (non-self-intersecting) polygon, regardless of how irregular its shape is.
Yes. Once you calculate, the Unit Conversions panel shows your result converted into every other supported unit automatically, so you don’t need to run a separate conversion calculation.