What is a skateboard measure in?

Skateboards come in all shapes and sizes, but generally the range from 7.5"-8.5" in width and 31"-32" in length. There are smaller boards for kids called minis and they can be as little as 7" in width and 29" in length. There are also much larger boards used for pool riding or just cruising that can be as wide as 10.5" and vary drastically in length. The board I ride is 8.25" x 31.125" and I skate street and pools.