Square Footage Calculator

Rectangle Area

Calculate the square footage, inches, yardage, meters or acres for landscaping, flooring, carpet or tiling projects. First calculate the area in square feet to find how much material you need. Then calculate the cost of materials by entering price per square foot, square inch, square yard or square meter.

Use the Calculator to Calculate Square Feet

1. Select your shape
2. Enter your measurements
3. Enter quantity if you need to multiply materials
4. Enter optional material waste factor
5. Enter optional cost as price per unit
6. Click Calculate to see calculations in square feet, square inches, square yards, square meters, acres, and cost if that applies

If your space is an irregular shape - like a rectangle plus a bump-out triangle for example - find the area for each section and then add them together.

Calculate Cost of Materials

Enter the price per square foot of material. If the price is in another unit of measure select that unit. The calculator finds the price for the total amount of material you need given the dimensions provide.

1. Enter the price per unit. For example if you are buying boxes of tile, each box will cover a specific number of square feet. Since you're likely charged per box, enter the price of the box and the number of square feet covered per box.
2. Select the unit of area. In the tile example you'd select "square feet" in the drop-down menu.

To calculate the volume of bulk materials like mulch or gravel, use our calculator for cubic yards and cubic meters.

How to Calculate Square Footage

Square footage is a way to quantify the area of a space where the dimensions, like length and width, are measured in feet. When you calculate the area, the resulting units are square feet. "Square" in front of any unit of measure simply means that you are measuring a flat 2-dimensional space and not 1-dimensional line, or a 3-dimensional volume.

Likewise, square yardage is area measured in yards and square meters is area measured in meters. You can also measure in feet, find the area in square feet, and then convert the area to a different unit of measure.

Basic Formula for Area

Area is the amount of space occupied by a 2-dimensional shape. The shape could be a floor or a wall, or something larger like a playground or a field.

The simplest formula for area is for a rectangular or square shape:

area = length × width

We show formulas for these and other more complex shapes in the section Area Formulas for Different Shapes.

Say you have a rectangular room and you want to calculate its area in square feet for carpeting. Measure the length and width of room and calculate length × width to get the area in feet squared or ft².

If your space has an odd shape, like an L-shape, split it into two or more square or rectanglular sections and calculate the area of each section. Add the two area measurements together for the total area.

If your measurements are in different units like inches and feet, first convert everything into feet. Multiply the length and width in feet to find the area in square footage.

Basic Length Conversion

Convert other units of measure to feet with these formulas.

• Inches to feet: Divide inches by 12 to get feet
• Meters to feet: Multiply meters by 3.28084 to get feet
• Centimeters to feet: Divide centimeters by 30.48 get feet
• Yards to feet: Multiply yards by 3 to get feet

CalculatorSoup® has a calculator to convert between other measures of length. See the Distance Conversion Calculator for an extensive list of length and distance units.

Area Conversion

You could measure your space in inches or centimeters, calculate area in square inches or square centimeters, then convert your final answer to any unit you need like square feet or square meters.

Use our Area Conversion Calculator to convert area between different units of measure.

Area Formulas for Different Shapes

Square Shape

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Calculate square footage of a square

Using measurements in feet: Area (ft²) = Side Length²

The formula to calculate area of any box shape is length × width. Since length equals width for a square, area is just side length squared.

Rectangle Shape

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Calculate square footage of a rectangle

Using measurements in feet: Area (ft²) = Length × Width

Rectangle Border Shape

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Calculate square footage of a rectangle border

Using measurements in feet: Inner Area (ft²) = Length × Width Total Area (ft²) = (Length + (2 × Border Width)) × (Width + (2 × Border Width)) Area (ft²) = Total Area − Inner Area

Wall and Window Shape

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Calculate square footage of a wall minus window

Using measurements in feet: Wall Area (ft²) = Wall Height × Width Window Area (ft²) = Window Height × Width Area (ft²) = Wall Area − Window Area

To subtract multiple windows of the same size from one wall, multiply window width by the number of windows. Enter this total as the window width in the calculator. Height remains the height of one window.

You can use the Wall and Window shape for a wall with one or more doors or other openings. Enter these dimensions in the Window Width and Window Height spaces.

Cathedral Wall

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Calculate square footage of a cathedral wall (right trapezoid)

Using measurements in feet: Area (ft²) = 1/2 × width × (height 1 + height 2)

This calculation is for a wall with a sloped top edge typical of walls of a room with a cathedral ceiling. The formal name of the geometric shape is a right trapezoid. An alternate method for this shape is to break the calculation into two components; a triangle and a square.

Circle Shape

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Calculate square footage of a circle

Using measurements in feet: Area (ft²) = pi × (Diameter ÷ 2)² pi = 3.14

This calculation uses diameter, the width of your circle. If you know only the radius, remember to multiply by two before entering it into the calculator: diameter = 2 × radius

For calculations by hand you can get higher accuracy in your square feet calculation by using pi = 3.14159265359. This is important for larger circle-shaped areas. This calculator uses a highly precise pi constant in its circle area calculations.

Circle Border Shape

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Calculate square footage of a circle border

Using measurements in feet: Outer Diameter = Inner Diameter + (2 × Border Width) Outer Area (ft²) = pi × (Outer Diameter ÷ 2)² Inner Area (ft²) = pi × (Inner Diameter ÷ 2)² Area (ft²) = Outer Area − Inner Area pi = 3.14

Annulus Shape

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Calculate square footage of an annulus

Using measurements in feet: Outer Area (ft²) = pi × (Outer Diameter ÷ 2)² Inner Area (ft²) = pi × (Inner Diameter ÷ 2)² Area (ft²) = Outer Area − Inner Area pi = 3.14 The Circle Border and Annulus are the same shape. Circle border area is calculated with border width, and annulus area is calculated with outer diameter.

Triangle Shape

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Calculate square footage of a triangle

Using measurements in feet: Area = √ { [ (a + b + c) ÷ 2) ] × [ (a + b + c) ÷ 2) − a ] × [ (a + b + c) ÷ 2) − b ] × [ (a + b + c) ÷ 2) − c ] } The sides of your triangle do not need to be the same length. Although the image shows a triangle with three equal sides, this formula works for any triangle shape.

Triangle Shape

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Calculate square footage of a triangle using base and height

Using measurements in feet: Area (ft²) = 1/2 × Base × Height

Trapezoid Shape

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Calculate square footage of a trapezoid

Using measurements in feet: Area (ft²) = [(a + b) ÷ 2 ] × h

Frequently Asked Questions

How do I calculate square footage for different shapes?

To find square footage, measure length and width for squares or rectangles, or use specific formulas and other measurements for other shapes, like circles and triangles, provided in our calculator for accurate results.

Can I convert between square feet and other units using this calculator?

Yes, our calculator lets you convert square feeet to square yards, inches, meters and acres, using the provided conversion factors for relevant measurements.

How do I measure for a construction project?

Input your area measurements to calculate the required quantity of materials like flooring, carpet or tiles, and find the costs using our price converter.

Can this calculator help with landscaping projects?

Yes, you can estimate the area and material needs for gardens, walkways or patios by calculating square footage and costs using our calculator.