User blog comment:Blaisem/Toughness vs. Tough Body/@comment-24659969-20141121181825/@comment-26533161-20160524044230

A level 100 heavy has a base health of 12100. Max tough body gives you a 54% damage reduction or, in technical terms, you suffer 46% of the damage you recieve. Max toughness gives you 7500 extra health.

Tough body effective health: 12100 / 0.46 = 26,304 effective health

Toughness effective health: 12100 + 7500 = 19,600 effective health

If you are a level 100 heavy that has 25 left over skill points to spend, spend it ALL on tough body. Don't balance it out either. If you have 13 toughness and 12 tough body, you effective health will be 21622. (Trust me on my calculations)