Hi Azalea, how old is your baby? You always want at least an inch from the top of your seat's shell and the top of your infant's head. For this reason, most car seats are outgrown by height before weight, so many infant seats are outgrown between 7-10 months old. In fact, many infant seats on the market have weight limits of 30 or 40 lbs! 30 lbs is the average size of a 3 year old, so your child will never reach that limit in their infant seat. Seat manufacturers tend to inflate those upper weight limits, knowing that your child will not reach them!

You can move to a convertible at any time, so it the seat feels too heavy you can switch when you are ready. Just be sure to transition to a convertible seat by your child's first birthday, if you choose to wait.

I just noticed that your baby is 8 months, Azalea. So, now is a great time to switch.

Hi Bridget, your 4 year old may still have time before maxing out the height and weight limits of your convertible, depending on which seat you have. Are they already forward facing?

Though a child may meet the minimum height and weight limits for a booster seat at 4 or 5, I strongly recommend kids remain harnessed until 6 years old. Most 4 and 5 year olds are just not mature enough to ride in a booster yet. They tend to be squirmy and have limited impulse control; many still fall asleep in the car seat. In a harness, the car seat is doing most of the work to keep the child properly positioned in the event of a crash. Once in a booster (with just the seat belt), the child is almost 100% responsible for maintaining a safe position.

If your child still has room to grow in the convertible FF, I would wait until you max out the limits of your current seat. If they are close to outgrowing the current seat, the next seat you would need is called a combination seat. It only installs forward facing--harnessed and then converts to a booster. Many combination seats have similar limits to convertibles on the market, but there are a few higher end options that harness to 70-90 lbs and accommodate a tall child.

What seat are you currently using? What is the height and weight of your 4 year old?

Hi Janel, we definitely want the harness to be routed through the slots that are closest to the child's shoulders (while remaining at or below shoulders RF). the gap between the "slanted" lower 3 sets of slots and the "straight" 2 upper sets is pretty big on Diono seats. If the next available slot is above the shoulders, you are using the correct one.

I would check the crotch buckle placement instead. There are 3 options and you want the one that is closest to, but *in front* of the child. They shouldn't be sitting on the webbing of the crotch buckle, which would make the harness difficult to tighten and feel tight for your kids. When they are sitting up tall in the seat, with their tushies all the way back (they tend to slouch when they get in), you should be able to see the crotch buckle in front of them. We want that crotch buckle to be parallel to or leaning into the body on Diono seats, so it is likely under them.

Are you engaging the ratchet harness?

That's super helpful - I'll check the crotch buckle next time they're in the seat. Didn't even notice there were other places to put that buckle! Sometimes I have to pull on their shoulder straps from the back of the carseat while pulling the long cord in the front in order to get it tight enough! If the next shoulder slot up is AT their shoulders, is that ok? I think that's where it hits.

What is the rachet harness?

At shoulder level is fine.
For the crotch buckle, make sure you change it in both the shell, foam, and cover. They always need to match (many parents just move it in the cover). Depending on your installation, you may need to uninstall the seat in order to adjust the crotch buckle position since you need to access it through the belt path.

The ratchet design is unique engineering that only Diono uses. Basically, you tighten the harness with a long pull followed by a tug, tug, tug. The long pull is standard for adjusting the harness on car seats, but the quick tugs in rapid succession are actually what makes the harness tight.

Thanks so much for this info - will check it out asap!