I have a bp cuff that fits standard to large. i have tried 3 different ways loose snug and tight got same reading very confused on how to fit cuff.

Snug: It shouldn't be loose, and shouldn't be so tight that it cuts off your circulation. So keep it snug above the elbow... I am assuming it is an automatic cuff that is giving you the readings? Regardless, you should follow up with a medical provider and take your cuff with you - so they can validate your technique, and also confirm your results for you.