The callus under my foot below my pinky toe stings and often makes my toe go numb it hurts to step on it as well do you know what it could be?

Nerve problem.: There are small nerves in the toes called digital nerves. When these nerves are irritated, such as from repetitive pressure as can occur with running or tight shoes, it is called a "digital neuropathy." these symptoms are also sometimes caused by a problem in the lower back, a "radiculopathy.".

Bursitis: It sounds like you have developed bursitis.

Different causes: Many things can cause calluses. Some reasons that one may develop a callus include: viral infections (warts), friction, pressure, repedetive trauma, and a limitation of joint motion. Some genetic conditions may also cause people to develop calluses on the hands and the feet. Treatment depends on the cause of the problem. Have it evaluated by a professional and get the appropriate treatment.