If all you are doing is programming of the everyday industry sort, none. You can have a fruitful interesting career from frontend to back without thinking about

If all you are doing is programming of the everyday industry sort, none. You can have a fruitful interesting career from frontend to back without thinking about formal math at all. If you want to start specializing in graphics or designing languages or algo, then, yeah, you'll need math, but at that point, you'll know what math. No need to learn it beforehand.