The answer to this question depends on the individual’s preference. A double XL size mattress provides 24 inches of space for each person which is almost same width as the crib. If you want to choose a Double XL size bed because of limited space or money, then you may have to check in with your partner for space and length constraints. For short persons, this may be sufficient but it can be a bit problem with taller sleepers. As mattresses are not one fit for all, we recommend to focus on which one works best for you.