Patio area calculator

How to use the patio area calculator

Use this calculator to find the area and outside edge length of a rectangular or round patio. Enter the patio dimensions in feet and inches or metres and centimetres to plan pavers, base gravel, bedding sand, and edge restraint.

1. Choose Feet / inches or Metres / cm.
2. Select Rectangle or Circle for the patio shape.
3. Enter Length and Width for a rectangle, or Diameter for a circle.
4. Add any extra inches or centimetres in the matching plus inches field.
5. Review the patio area and perimeter or circumference in the results.

What to enter

Unit system

Choose Feet / inches for US customary measurements or Metres / cm for metric measurements. The default is Feet / inches.

Shape

Select Rectangle for a length-and-width patio or Circle for a round patio. The default is Rectangle.

Length

Enter the patio length in feet when using imperial units or metres when using metric units. The default is 12.

plus inches

Add the remaining inches to the length. In metric mode, enter the additional centimetres. The default is 0.

Width

Enter the patio width in feet or metres. This field applies to rectangular patios. The default is 10.

plus inches

Add the remaining inches to the width. In metric mode, enter the additional centimetres. The default is 0.

Diameter

Enter the outside diameter of a round patio in feet or metres. This field applies to circle patios. The default is 12.

plus inches

Add the remaining inches to the diameter. In metric mode, enter the additional centimetres. The default is 0.

Example: 12 ft by 10 ft rectangular patio

With Feet / inches selected, keep Rectangle, enter Length 12, Length plus inches 0, Width 10, and Width plus inches 0. Area: 12 × 10 = 120 sq ft. Perimeter: 2 × (12 + 10) = 44 ft. The results also show 120 × 0.092903 = 11.15 m² and 120 ÷ 9 = 13.33 sq yd, rounded to two decimals.

How the patio area is calculated

For a rectangle, the calculator converts feet and any added inches into decimal feet, then uses area = length × width and perimeter = 2 × (length + width). For a circle, it converts the diameter into decimal feet, then uses area = π × (diameter ÷ 2)² and circumference = π × diameter. Results are rounded to two decimals. Metric inputs are converted internally and reported in m² and metres, while the breakdown also includes square feet, square yards, and feet.

Reading the results

The primary results show Patio area and either Perimeter for a rectangle or Circumference for a circle. Use area to estimate the surface covered by pavers, base gravel, or bedding sand. Use the outside edge measurement to plan edge restraint. The breakdown provides both US and metric area and edge measurements.

Limitations and common mistakes

• This tool calculates area and the outside edge length only. It does not calculate paver counts, base depth, sand volume, or material cost.
• For a circle, measure the outside diameter of the patio. A curved layout may require additional cutting allowance beyond the area result.
• The rectangle result assumes straight sides and measures to the outside edge of the paving, including any border course.
• All dimensions must be positive. Added inches or centimetres can be zero, but the main length, width, or diameter cannot be zero.

Frequently asked questions