Okay,so I'm pretty confused on how to do the formula on how much a horse can carry.

My horse is 950 lbs. She is a bit chubby now but looks good.

Anyways,I heard the 20% rule or you can take the horses weight and divide it by 6 and you get the number on what the horse can carry including tack.....well then I would be too big for my horse! Because it came up to 158 inluding tack. I weigh 162 on a good day(my weight varies a few lbs). I would say my tack can weigh 25 lbs total and that's for my treeless and my english tack is a lot lighter....soooo my big butt is to much for my horse.....I am really worried about my weight when it comes to riding.I think a lot of it is muscle but I do have fat.

I don't get to how to do the 20% formula....