This fabric has the highest possible sun protection rating of UPF 50+ Excellent Protection.
What is impressive is that it is designed to be a high performance fabric. The fact that it also offers excellent protection with a UPF rating of 50+ shows that you can have performance without the need to compromise on protection.
Measure the circumference and/or width of your hand at the knuckles. The circumference will give better results, but the width is easier if you don't have a tape measure.