For how long should my baby feed in one sitting?

It varies...: ...Although most babies get all their milk in 5-10 minutes and nurse the rest of the time for entertainment and comfort.

Depends: The amount of time your baby spends feeding is not as important as the quality of the feed. Some babies are faster than others at feeding, so it is hard to quantify the appropriate time. You should stop a feeding when your baby pulls away from the nipple and appears satisfied.

Until they are done: The length of time at the breast is not a good indicator of how well the feeding has gone. A baby can spend an hour at the breast, but if the latch is poor, may not have transferred much milk. They could also spend 10 minutes and get all they need. Babies love to hang out at the breast and breastfeeding is so much more than food. I'd stop watching the clock and enjoy the time with the baby.

Not very long: Feed when baby is happy and interested to eat. Stop feeding the baby when baby shows signs of fullness : 1. Baby is not interested to open mouth. 2. Baby's head turns when seeing the spoon coming. 3. Baby is getting restless or angry. 4. Baby is spitting out most of the food. 5. Baby has big burped and hiccups.

Depends on age: If your baby is breastfeeding how long he is on the breast depends on his age. In the beginning he's still learning how to nurse effectively and your body is still mastering the let down process. In the first few weeks each feed may take 40 minutes (10-20 minutes on each breast). By the time his 6 months old you'll both be more efficient and he'll spend 5 minutes per side and be back to playing.