After months of training, the best way to test ones self is to spar in full contact. For safety reason, wear body armour, groin guard and maybe shin guard. Spar with open fist. And try to land a power penetrating punch at each other no head blows only body attack.
A well place punch with penetrating power would penetrate the body armour and would either fracture or cuase bruises on your opponent. A punch like that would knock the win out of your oppoenent making him unable to continue the fight, then would you know that your punch has that speed and penetrating power.
The body armour can be like the ones that tae kwan do uses or armour reinforce with bamboo sticks like kendo armour.