Calc

Square Footage Calculator

icon of a measuring tape

Use this square footage calculator to work out an area of square feet, square meters, square yards or acres for construction projects, flooring, landscaping, carpets, tiling and more. This tool also provides a cost of materials estimate. If you're measuring a room for flooring, take a look at our article on how to measure for a new floor.


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Disclaimer

Whilst every effort has been made in building this square footage calculator, we are not to be held liable for any special, incidental, indirect or consequential damages or monetary losses of any kind arising out of or in connection with the use of the converter tools and information derived from the web site. This square footage calculator is here purely as a service to you, please use it at your own risk. Do not use calculations for anything where loss of life, money, property, etc could result from inaccurate conversions.

Please see the full disclaimer for more information.


How do I calculate square feet?

Square feet is a unit of area. Calculating square footage requires you to take a couple of measurements and then do some simple multiplication. Let's assume in this example that you want to work out the area of a rectangular room for flooring or carpet. Should you wish to calculate the square footage of a circular or triangular area, you'll find instructions further down.

Calculating square footage of your area

  1. Measure the Width and Length of your rectangular area. If your measurements are in feet, skip to step 3.
  2. If your measurements aren't in feet, convert them to feet (converter available):
    • If in inches: divide each by 12.
    • If in yards: multiply each by 3.
    • If in cm: multiply each by 0.03281.
    • If in m: multiply each by 3.281.
  3. Multiply your Length × Width = Area.

This gives you your area in square feet (ft2). To work out your cost of materials, simply multiply this figure by your 'cost per square feet'. For other area shapes (circles, triangles), instructions and formulae are below. Should you wish to convert to acres, give the square feet to acres converter a try.


How to calculate the square footage of a house - example

Supposing you want to measure the square footage of an area that isn't one single rectangle? This example video, from Mathispower4u, shows you how to divide your area up into smaller rectangles in order to calculate the overall square footage.

Calculating square footage for a circular area

Diagram of circle
  1. Measure the diameter of your circle in feet.
  2. To calculate the area of a circle we use the formula: π x (diameter/2)2. That is to say π (pi is 3.14159265) multiplied by half the diameter squared. So, we divide our diameter by 2 and then square it (multiply it by itself) and then multiply by π.
  3. This gives you your square feet figure (ft2). To work out your cost of materials, simply multiply this figure by your 'cost per square feet'.

The formula for calculating the area of a circle is: π r2 (with r being the radius of the circle, which is half the diameter). π is the symbol for pi (3.14159265).


Calculating square footage for a triangular area

Diagram of triangle
  1. Measure the length of the base of the triangle and the height of the triangle.
  2. To calculate the area of a triangle we use the formula: (base x height) / 2. That is to say we multiply the base by the height and then divide it by 2.
  3. This gives you your square feet figure (ft2). To work out your cost of materials, simply multiply this figure by your 'cost per square feet'.

The formula for calculating the area of a triangle is: base x height / 2.


If you have any problems using the square footage calculator tool, please contact me.