How Well do I sleep?

I think I sleep quite well I try to get 8-9 hours every night and often go to bed earlier if I have to wake up earlier in the morning for swimming. I think I could improve and not look at screens before I sleep as I know that can have an effect on how well you sleep. On the weekends especially Saturday night, since I don’t have to wake up for anything on Sunday I sleep for like 10-11 hours so I can recharge my batteries.