An all-in-one car seat is a convertible seat that’s designed to work from the baby days all the way through the big kid years. Many all-in-one seats boast a lifespan of about 10 years, meaning that instead of purchasing three (or even four) different seats as your child grows, you’ll only need to purchase one.

All-in-one seats transform from rear-facing seats to forward-facing ones, then ultimately to booster seats. (Some convert to both highback and then backless boosters, while other models end up only as highback booster seats.)