Box Jump Max

Last night I went for my max height on box jump. unfortunately I dont know how high it was but we used the plastic steps, 20 high, plus the box top (which is about the same height as one of the "steps" or leaflets). So once I figure out how high that was I'll post it. It was just above waist height on me. I did jump 21 + the top, but couldn't stand on top so I didn't count it.