Why is my backup 9.54 GB

My phone won’t backup because I only have 5 GB of iCloud storage. I’m only using 4MB of data on it so it’s pretty empty, but for some reason the backup needs to take 9.54 GB, even though the apps that are being backed up only amount to 555MB, I don’t even save photos on the cloud so that isn’t it. I really don’t want to pay for extra iCloud storage, so what should I do?