Will pull ups help increase the size of my back?

Yes, pull ups can help increase the size of your back. But so can pulldown and rowing motions. The key is to apply the correct amount of stimulus to the muscle (sets, repetitions, load), proper rest between training sessions and nutrition that will ultimately help you increase size in your back.

Pull ups are a great exercise for increasing the overall width of your back. Primarily a lat exercise, pull ups also recruit the biceps and come in many variations. Underhand pull ups (chin ups) are the easiest, followed by neutral grip, then overhand, with wide grip being the most challenging. Body weight or weighted pull ups should be a staple in your back routine to increase size and back width. Incline pull ups are another variation which focus more on the rhomboids or middle back. Incline pull ups will help develop back thickness.