Google it is the obvious answer. You'll find that body fat is an elusive number to quantify with different methods of assessing, none of which are very accurate. Using one method consistently will tell you how you are doing relative to how you were doing. It will help you track progress.
You can use calipers, BIA (scales and hand held), Dexa-scan, water displacement, tape measure, and probably a few other ways. Most argue that Dexa or water displacement are the most accurate but they have their flaws. I saw a dude that posted a picture of himself and there was no way he was over 12 percent and he had just had a water displacement measurement that put him at 23 percent (he had a six pack, not abs, a six pack).
For experienced folk, the mirror might be the best measure. You can get an idea of what different percentages look like by googling it and comparing yourself, but those are still inaccurate.
So, you might be in that range. Bodybuilders are in that range but with a hell of a lot of lean body mass. You could be six percent but at 6 feet tall and 135 pounds, you're not going to impress any judges. It all depends on the total package.
Hehe, I said package.