I keep about a $300 buffer in the account. That would cover all of my automatic withdrawal bills plus a little extra, in case I “space” something for some reason. I do about $60/month for car maintenance, that covers tags, oil for changes (we do our own) and parts of need be, but we know we need to get a new part for my car this month, so I bumped that amount up to $80 for this month just to give ourselves a little bit extra and my husband has overtime.