The younger a vampire is, the more they have to feed to maintain power, the following list is in OOC time for the time you have to feed once before your power starts to decline.
Fledgeling - One day
Sanguine - One day
Adept - Two days
Veteran - Three days
Elder - Four days
Master - Five days
Fledgeling - One day
Sanguine - One day
Adept - Two days
Veteran - Three days
Elder - Four days
Master - Five days