No matter where you get a tattoo it is painful. You are letting someone stick you with a needle there's no way to keep that from hurting. I was able to tolerate it more on the calf of my leg. But it still hurt.
The least painful area to get tattooed is an area where you have a lot of fat and few bones. The calf, the thigh, and the stomach are areas that many people find less painful to get tattooed. Avoid getting a tattoo right on the bone anywhere on the body. This will definitely hurt.