Area Calculator

This area calculator finds the surface a flat shape covers for the five shapes that come up most often: the rectangle, the triangle, the circle, the trapezoid and the parallelogram. Area is measured in square units and it is one of the most practical calculations in everyday life. Working out how much paint, turf, carpet, tiles or paving you need, how much a section measures, or the size of a garden bed all start with an area. You select the shape, enter its dimensions in any unit you like as long as they all match, and the calculator applies the correct formula and returns the area in square units. The formulas are worth knowing: a rectangle is length times width, a triangle is half the base times the perpendicular height, a circle is pi times the radius squared, a parallelogram is base times height, and a trapezoid is half the sum of its two parallel sides times the distance between them. For odd shapes, a useful trick is to split the space into these standard shapes, work out each area, and add them together. The result here is exact within normal precision and updates as you type. Choose your shape and enter the measurements to see the area straight away.

Keep all dimensions in the same unit; the area is in those units squared. Estimate only.