Square Footage Calculator
Disclaimer: Whilst every effort has been made in building this calculator, we are not to be held liable for any damages or monetary losses arising out of or in connection with the use of it. This tool is here purely as a service to you, please use it at your own risk. Full disclaimer. Do not use calculations for anything where loss of life, money, property, etc could result from inaccurate calculations.
How do I calculate square feet?
To calculate an area in square feet, you will need measurements for the width and length (for a square shape) or the diameter (for a circular area). It may be that the area you're looking to measure is a strange shape (such as a room or garden). In this case, dividing it up into smaller parts and doing individual calculations is a good way to calculate the overall square footage.
Let's say you have a rectangular-shaped room and you want to calculate the square footage area for flooring or carpet. The easiest method for calculating the square footage is to measure the length and width in feet and then multiply the two figures together to give you a result in ft2. If you're measuring a room for flooring, take a look at our article on how to measure for a new floor.
Should you find yourself needing to calculate an area of square feet in an 'L' shape, consider dividing the shape up into rectangular sections and treating them as separate areas for calculation (adding them together at the end).
Calculating square footage of your area
- For a square or rectangular area, measure the Width and Length in feet.
- Multiply your Length × Width to get your area.
Note: If your measurements aren't in feet, convert them to feet first using the instructions below or the length converter.
- If in inches: divide each figure by 12 to get feet measurement.
- If in yards: multiply each figure by 3 to get feet measurement.
- If in cm: multiply each figure by 0.03281 to get feet measurement.
- If in m: multiply each figure by 3.281 to get feet measurement.
Once you've carried out your calculation, you will have your square feet (ft2) figure. To calculate 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. If you would like to convert your figure into cubic feet, take a look at the square feet to cubic feet calculator.
Of course, it may be that the area you're measuring isn't rectangular. Instructions on calculating for a circular area and triangular area are further down.
How many square feet are in a 10x10 room?
To answer this question, we simply multiply the length of the room by the width. If your room is 10 feet long by 10 feet wide, 10 × 10 = 100 square feet.
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? In this example video from Mathispower4u you can find out how to divide your area up into smaller rectangles in order to calculate the overall square footage.
Calculating square footage for a circular area
- Measure the diameter of your circle in feet.
- 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.
- 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).