Most toddler beds are around 50" to 60" long, whereas a twin bed is 80" long. Most kids will use a toddler bed for a couple of years before moving to a twin or full bed, although the timeline is different for everyone. Generally, we recommend that parents make the switch straight to a big kid bed, whether that be a twin-size or full-size kids mattress. Not only does this minimize the number of sleep transitions you have to make, but it also can help you save money by investing in a longer-lasting mattress. However, if space is a major issue, a toddler bed can make a lot of sense. Ultimately, it depends on your specific needs and what your child is ready for – and that's something only you can decide.