Rectangle Calculator

Area measures the two-dimensional space enclosed by the rectangle — how much flooring, fabric, or paint you'd need to cover its surface. Perimeter measures the one-dimensional distance around its outside edge — how much fencing, trim, or border material you'd need to wrap it. The two don't scale together: a rectangle can be made longer and narrower while keeping the same area but increasing its perimeter substantially.

No — area and perimeter are both symmetric in width and height, so swapping the two values gives identical results. The labels exist purely to help you keep track of which physical dimension is which when you're reading numbers off a real object; the math doesn't distinguish between them.

A square — a rectangle with equal width and height — always encloses the most area for a given perimeter, and the more elongated a rectangle becomes for that same perimeter, the less area it holds. This is a useful rule of thumb when designing an enclosure with a fixed amount of fencing or trim material and wanting to maximize usable space inside it.

Enter width and height in whichever unit you have (feet, meters, inches), and the area comes out in that same unit squared and the perimeter in that same linear unit. To switch units afterward, multiply the area by the appropriate squared conversion factor — for example, multiply square feet by about 0.0929 to get square meters — since area conversions require squaring the linear conversion factor, not applying it once.