At 13 months, most toddlers do well with about 3-4 feeds a day, morning, lunch time, evening, and before bed, though honestly it varies a lot depending on how much solid food they're eating and how hungry your little one is. A few of us mums find that around 16-24 oz daily (combined with meals) works, but some kids need more or less, so just watch your child's weight gain and energy levels lah, if he's growing well and seems satisfied, you're on the right track!