Surface Area of a Rectangle Calculator

Surface Area of a Rectangle

For a 2D rectangle, the surface area is the same as its area. Multiply length by width:

$$A = \ell \times w$$

where $\ell$ is the length and $w$ is the width. Both dimensions must use the same unit before multiplying.

A rectangle with length 8 m and width 5 m has area:

$$A = 8 \times 5 = 40 \text{ m}^2$$

Perimeter: $P = 2(\ell + w)$. Diagonal: $d = \sqrt{\ell^2 + w^2}$.

Is surface area the same as area for a rectangle?

Yes. For flat 2D shapes, surface area and area refer to the same measurement.

What units should I use?

Length and width must share the same unit. The area is in square units (m², ft², cm², etc.).

How do I convert rectangle area to square meters?

Convert both sides to meters first, then multiply. Or multiply in your chosen unit and apply the appropriate area conversion factor.

Can length and width be in different units?

Not directly. Convert one dimension to match the other before calculating area.