These soccer cleat fit tools help with the questions a size chart does not answer. You can see how wide your foot is, which of two sizes to pick, how sizes convert and what to do when a pair pinches. If you already know what you need, the cleat finder gives you three picks right away.
If you do not own cleats yet, start with your foot width. You need a sheet of paper, a pen and a ruler. Measure at the end of the day, wearing the socks you play in, because your foot is biggest then. Take the result to the finder so you only see models that suit that width.
Between two sizes? Use the between-sizes tool, which also weighs the material. If your cleats already pinch, start with the pinch tool: it shows whether different lacing might help.
The tools are a starting point, because every foot and every last is different. The rules come from our fit method. Trying on is the last step, at home on a clean floor in your own soccer socks. If you have pain, see a podiatrist.