I have a solid mass on my calf, which is painful. my doctor has said it is fat or lipoma. from what i have read, lipomas are not supposed to hurt?

They can: Lipomas are fatty tumors. They are not cancer. But they can sometimes cause pain. If you're having pain, see your surgeon for possible removal.

You are right: Lipomas are a type of fatty tumor. They are normally painless. They can cause pain if they press on a tender area. They can also cause pain if they pinch or compress a nerve. If the mass itself is tender you should ask your doctor about the symptom or get a second opinion to be sure.