While the location your umbrella will be placed is often the first consideration, the primary decision is what size and shape to purchase since most manufacturers offer similar sizes and colors.
The shape and size of your umbrella – octagon, square or rectangle will determine how much shade coverage your area will receive.While most companies refer to umbrellas as “round” they are actually “octagons”.
So when you compare a 10 foot square umbrella to a 10 foot round/octagon umbrella the numbers tell the full picture.
A 10 foot square umbrella has a shade are of 100 square feet while a Round/Octagon has approximately 71 square feet. So a square will give you almost 30% MORE shade coverage.
If you are looking for maximum shade protection: a square umbrella is the way go!