# Square Footage Calculator

## Calculate a *Annulus* Area

## Calculator Use

Use this calculator to find the square footage, square inches, square yardage, square meters or acres for a building, home, garden or construction project. Calculate square footage, inches, yardage, meters and acres for landscape, flooring, carpet, or tiling projects to estimate area and the amount of material you will need. Also calculate the cost of materials when you enter the price per square foot, price per square inch, price per square yard or price per square meter.

Price is entered in the fields, for example, as

$ price: 3.00 per: 1
square unit: foot (ft²)

meaning $3.00 per 1 square foot

or

$ price: 25.00 per: 1000
square unit: foot (ft²)

meaning $25.00 per 1000 square feet

etc ....

If you want to calculate volume of bulk materials such as mulch or gravel you should use our calculator for cubic yards and cubic meters.

Enter measurements in US units or metric units. Calculate area from your measurements in inches (in), feet (ft), yards (yd), millimeters (mm), centimeters (cm), or meters (m). You can also enter decimal values. For example, if you have one measurement that is 7'3" you can enter that as 7.25 feet (3"/12" = 0.25 ft). If you have a measurement of 245 cm you can also enter that as 2.45 m.

## How to Calculate Square Footage

Square footage is area expressed in square feet. Likewise, square yardage is area expressed in square yards. Square meters is also a common measure of area.

Assume you have a rectangular area such as a room and, for example, you want to calculate the square footage area for flooring or carpet.

The way to calculate a rectangular area is by measuring the length and width of your area then multiplying those two numbers together to get the area in feet squared (ft^{2}). If you have on oddly shaped area, such as an L-shape, split it into square or rectanglualar sections and treat them as two separate areas. Calculate the area of each section then add them together for your total. If your measurements are in different units, say feet and inches, you can first convert those values to feet, then multiply them together to get the square footage of the area.

### Measure

- Measure the sides of your area

### Convert all of your measurements to feet

- If you measured in feet skip to "Calculate the Area as Square Footage"
- If you measured in feet & inches, divide inches by 12 and add that to your feet measure to get total feet
- If you measured in another unit of measure, do the following to
convert to feet

- inches: divide by 12 and that is your measurement in feet

- yards: multiply by 3 and that is your measurement in feet

- centimeters: multiply by 0.03281 to convert to feet

- meters: multiply by 3.281 to convert to feet

### Calculate the Area as Square Footage

- If you are measuring a square or rectangle area, multiply length times width; Length x Width = Area.
- For other area shapes, see formulas below to calculate Area (ft
^{2}) = Square Footage.

## Convert among square inch, square foot, square yard and square meter

You could, for example, perform all of your measurements in inches or centimeters, calculate area in square inches or square centimeters then convert your final answer to the unit you need such as square feet or square meters.

To convert among square feet, yards and meters use the following conversion factors. For other units use our calculator for area conversions.

- Square Feet to Square Inches
- multiply ft
^{2}by 144 to get in^{2}

- multiply ft
- Square Feet to Square Yards
- multiply ft
^{2}by 0.11111 to get yd^{2}

- multiply ft
- Square Feet to Square Meters
- multiply ft
^{2}by 0.092903 to get m^{2}

- multiply ft
- Square Yards to Square Feet
- multiply yd
^{2}by 9 to get ft^{2}

- multiply yd
- Square Yards to Square Meters
- multiply yd
^{2}by 0.836127 to get m^{2}

- multiply yd
- Square Meters to Square Inches
- multiply m
^{2}by 1,550 to get in^{2}

- multiply m
- Square Meters to Square Feet
- multiply m
^{2}by 10.7639 to get ft^{2}

- multiply m
- Square Meters to Square Yards
- multiply m
^{2}by 1.19599 to get yd^{2}

- multiply m

## Square Footage Formulas and Images for Different Areas

### Square Area

#### Calculate square footage for a square area

Using measurements in feet:

Area (ft

^{2}) = Side Length x Side Length

### Rectangle Area

#### Calculate square footage for a rectangle area

Using measurements in feet:

Area (ft

^{2}) = Length x Width

### Rectangle Border Area

#### Calculate square footage for a rectangle border area

Using measurements in feet:

Inner Area (ft

^{2}) = Length x Width

Total Area (ft

^{2}) = (Length + (2 x Border Width)) x (Width + (2 x Border Width))

Area (ft

^{2}) = Total Area - Inner Area

### Circle Area

#### Calculate square footage for a circle area

Using measurements in feet:

Area (ft

^{2}) = Pi x (Diameter/2)^2

Pi = 3.14

### Circle Border Area

#### Calculate square footage for a circle border area

Using measurements in feet:

Outer Diameter = Inner Diameter + (2 x Border Width)

Outer Area (ft

^{2})

= Pi x (Outer Diameter/2)^2

Inner Area (ft

^{2})

= Pi x (Inner Diameter/2)^2

Area (ft

^{2}) = Outer Area - Inner Area

Pi = 3.14

Obviously, the Circle Border and Annulus are the same, just measured differently.

### Annulus Area

#### Calculate square footage for a annulus area

Using measurements in feet:

Outer Area (ft

^{2})

= Pi x (Outer Diameter/2)^2

Inner Area (ft

^{2})

= Pi x (Inner Diameter/2)^2

Area (ft

^{2}) = Outer Area - Inner Area

Pi = 3.14

Obviously, the Circle Border and Annulus are the same, just measured differently.

### Triangle Area

#### Calculate square footage for a triangle area

Using measurements in feet:

Area (ft

^{2}) = (1/4) x square root[ (a+b+c) x (b+c-a) x (c+a-b) x (a+b-c) ]

### Trapezoid Area

#### Calculate square footage for a trapezoid area

Using measurements in feet:

Area (ft

^{2}) = ((a + b) / 2 )h