I looked at both 14 and 15 inch a lot at the Apple store and while the 14 inch is bigger i found it closer to the 13 inch in terms of space. Now i did this, based on a slightly larger display resolution. I made the display resolution one side to the left on the 15 inch and did the same with the 14 inch because i know that’s what i needed based on my mid-40s eye sight. I went for the 15 inch as a result. Hope this helps.