Rectangle Dimensions
Perimeter & Properties
A Perimeter of a Rectangle Calculator is a dedicated math tool used to find the exact continuous distance around the outside boundary of a rectangular shape. Finding the perimeter is a common task in fencing a yard, framing a picture, or placing baseboards in a room.
How the Perimeter is Calculated
A rectangle has four straight sides. The opposite sides are always equal in length. This means there are two identical length sides and two identical width sides. To find the perimeter, you simply add all four sides together.
The standard mathematical formula is: Perimeter = 2 × (Length + Width)
Alternatively, you can use: Perimeter = (2 × Length) + (2 × Width)
For example, if a garden is 15 feet long and 8 feet wide, you first add 15 and 8 to get 23. You then multiply 23 by 2. The total perimeter around the garden is 46 feet.
How to Use This Calculator
- Enter the measurement for the long side into the Length input.
- Enter the measurement for the short side into the Width input.
- Make sure both of your numbers use the same unit of measurement (like meters or inches) before calculating.
- The calculator will instantly reveal the Total Perimeter, alongside the Area and Diagonal lengths for extra convenience.
Frequently Asked Questions
What is the difference between Perimeter and Area?
Perimeter measures the outline or the border of the shape. It is a one-dimensional measurement (like taking a string and wrapping it around the outside). Area measures the flat, two-dimensional space inside the boundaries of the shape (like covering the floor with carpet).
Why is there no squared symbol on the perimeter unit?
Because perimeter only measures a straight, continuous line. When you add feet to feet, the answer remains in feet. You only use a squared symbol (²) when you are multiplying length by width to find the flat Area.
Can I find the perimeter if I only know the Area?
No, not without more information. Many different rectangles can share the exact same area but have completely different perimeters. For example, a rectangle that is 10x2 has an area of 20 and a perimeter of 24. A rectangle that is 5x4 also has an area of 20, but its perimeter is only 18. You must know both sides, or know the area and at least one side, to find the perimeter.