# US Standard Area

These are the most common measurements:

**Square Inch****Square Foot****Square Yard****Acre****Square Mile**

Small surfaces are usually measured in square inches, rooms and buildings in square feet, carpet in square yards, property in acres, and territory in square miles.

## Square Inch

Area is length by length, so a **square inch** is a square that is 1 inch on each side.

The Unit is **inch × inch**, which can be written many ways, such as:

- in
^{2} - inch
^{2} - sq in
- sq inch
- square inch
- etc ...

## Square Foot

A **square foot** is a square that is 1 foot on each side.

Here Ariel the Dog sits next to a square foot made with tape measures.

The Unit is foot × foot, which can be written many ways, such as

- ft
^{2} - foot
^{2} - sq ft
- sq foot
- sq feet
- etc ...

## Square Yard

A **square yard** is a square that is 1 yard on each side. It is equal to 9 square feet.

## Acre

One **acre** is equal to 43,560 square feet.

It is roughly equal to a** football field** in area.

It is exactly the area 66 ft by 660 ft.

Or 198 ft by 220 ft.

Acres are commonly used to measure land.

## Square Mile

A **square mile** is a square that is 1 mile on each side.

Square miles are commonly used to measure large areas of land.

## More Examples

A square inch is about:

- 6½ square centimeters

An acre is:

- 4,840 square yards
- 43,560 square feet
- 4,046.8564224 square meters
- a square with sides about 208.71 feet (or 69.57 yards)
- about 0.4 hectare (40% of the area of a hectare)
- a bit less than a football field
- about 16 tennis courts

A square mile is:

- 640 acres