Area Calculator

Find the area of a rectangle from its length and width, the most common area sum. For a circle, triangle or other shape, use the linked pages below.

Area of a rectangle
×
Result
Area15 units²
Perimeter16 units
Quick answer
The area of a rectangle is length × width. A 5 by 3 room is 5 × 3 = 15 square units, and its perimeter, the distance around the edge, is 2 × (5 + 3) = 16. Whatever unit you measure in, the area comes out squared: metres give square metres, feet give square feet.

How it works

lengthwidth
Area = length × widthperimeter = 2 × (length + width)
length
one side of the rectangle
width
the side next to it
Area
the space inside, in square units

Enter both sides in the same unit. If you measure in feet the area is in square feet; a square that is 1 yard on each side is 9 square feet, not 3.

Frequently asked questions

How do you find the area of a rectangle?

Multiply the length by the width. A 4 by 6 rectangle has an area of 24 square units.

What is the area of a 10 by 12 room?

120 square feet, if the sides are measured in feet.

What is the difference between area and perimeter?

Area is the space inside a shape, in square units; perimeter is the distance around its edge, in plain units.

How do I find the area of a square?

A square is a rectangle with equal sides, so multiply the side by itself. See the square page.

What units is area measured in?

Square units, matching your input: square metres, square feet, square inches and so on.

Related conversions

Different shape? Area of a circle uses the radius, area of a triangle uses base and height, and a square needs just one side. There are also pages for a trapezoid, a parallelogram and an ellipse.