How to Calculate the Square Feet of a Deck

You must measure each side of your deck in order to figure the square feet.

Finding this calculation will help you to plan for materials and costs, or it will give you a description that you can offer to potential buyers.

1. Measure each side of your deck with a tape measure.

2. Draw a sketch of your deck and write in the measurements of each side.

3. Divide the drawing into squares, rectangles and triangles. If your deck is one big rectangle or square, you won't have to divide the drawing. However, if your deck has an irregular shape, you must break this shape into smaller sections.

4. Calculate the area of each shape within the sketch of your deck. In order to figure the area of rectangles and squares, multiply the length times the width. If you have a triangle in your sketch, multiply the height times the base and divide by two.

5. Add the areas of the individual shapes to find the total square feet contained within your deck. If your deck is square or rectangular, you won't have to add individual areas. You will only have to multiply the length times the width.