Patio umbrellas help to keep your deck and patio tables cooler by providing shade from the sun. They can also help provide shade for your chair cushions to prevent fading from the sun. You should know what size umbrella that you need to cover your desired area before you shop for an umbrella. You can measure your current umbrella size if you are looking to replace the one that you have.
Open the umbrella so that it is fully extended.
Measure the top of your umbrella along one of the rib arms. Use a tape measure to measure from the top center to the outside edge.
Multiply that number by two. This will give you correct size of your umbrella. Patio umbrellas are measured by their width and not their height.
Take another measurement from the base of the umbrella pole to the crank mechanism. This will give you the measurement of the crank height. You need to know this measurement if you are measuring for a patio table.