Concerned with iPhone 5s battery life

hello everyone,

i'm a little bit concerned with the battery life of my iPhone 5s which i got brand new 1 month ago.I have had an iPad Air for ayhear or so now and the difference in battery life might be making me confused...anyway.

My iPhone (in contrast with the iPad) loses 1% per hour while in sleep mode,without even being used.Ex.I charged it at 9PM and at 3 PM of the next day,with no use AT ALL it was down to 75% while my iPad which was charged at 9PM as well and after having watched 2 hours of YouTub,at 3PM was at 80%

I understand that since the iPhone is smaller,it's normal to have a bit worse battery life,but Apple claims 8 hours which I dont seem to be able to get.

NOte that iPhone and the iPad have exactly the same settings thus it's no dofference between background apps And both run on iOS 8.3

is it really useless to compare these 2 devices?Is my iPhone battery ok?I can add the battery life of the iPad and provide more examples if you want me to