Personal injury damages are a human formula problem, not a math formula problem.
Insurance companies routinely challenge medical bills, even if you are just following your doctor’s instructions and trying to get better.
Even when medical bills are determined, the pain and suffering and loss of enjoyment of life damages are determined by how the injuries have affected you and your life. There is no arbitrary math formula for figuring this out, because you are a human being and your life and your enjoyment of it have intrinsic human value.