GeomBench

Perimeter Calculator

The distance around a rectangle from width and height.

Perimeter is about the boundary, not the inside

Where area tells you how much surface something covers, perimeter tells you how much material traces its edge — fencing, trim, or the wire around a garden bed.

A common mix-up

It's easy to accidentally compute area when you need perimeter (or vice versa) — always double-check which one your project actually calls for before ordering materials.

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GeomBench

Perimeter Calculator

The distance around a rectangle from width and height.

Width

Height

Perimeter

P = 2(w + h)

Area: 40

What you entered

Width: 8Height: 5

1
Area
8 × 5= 40
2
Perimeter
2 × (8 + 5)= 26
3
Diagonal
√(8² + 5²)= 9.434

Result

Perimeter: 26

A 8 × 5 rectangle has a perimeter of 26.

Perimeter is about the boundary, not the inside

Where area tells you how much surface something covers, perimeter tells you how much material traces its edge — fencing, trim, or the wire around a garden bed.

A common mix-up

It's easy to accidentally compute area when you need perimeter (or vice versa) — always double-check which one your project actually calls for before ordering materials.