Convertible seats are designed to be used both rear facing and forward facing. They can be used as your baby's first car seat or as the "next step up" from her infant seat.
Age, Weight & Height Limitations
Many convertible seats will accommodate a newborn baby. The key here is to make sure that the lowest harness slot setting is at or below the baby's shoulders and that the baby is within the weight limits of the car seat. If either of these cannot be met then you will need to choose another car seat.
There is no upper age limit for a convertible seat, especially now that many have much higher weight limits. Just remember that it's best to keep a child rear facing longer (until two years old if they still fit) and, once you turn him forward, in a harness longer (many seats have weight limits to 50 & 60 pounds or more).
All convertible seats currently have a starting weight limit of 5 pounds. This means that if you have a low birth weight baby you'll need to start with an infant car seat that has a lower weight limit or a car bed (if the baby didn't pass the apnea car seat study at the hospital).
Most have an upper weight limit of 35 pounds, one or two max out at 22 pounds (not recommended) and a few reach 40 or 45 pounds (great for rear facing longer!).
The forward facing starting point for most convertible seats is generally 20 or 22 pounds, HOWEVER, many babies will not even be a year old at that point and therefore CANNOT be turned forward facing safely.
The forward facing maximum weight limit varies a great deal depending on which seat you have. It typically ranges from 40 to 65 pounds, but you'll fine one or two out there that go to 80 pounds.
An important key here is to not only watch for the weight limit, but the upper harness slot height as well. If a seat goes to a higher weight limit, but has a low top harness slot, your child may outgrow the height limit without coming close to the weight limit. Take a tape measure with you when shopping for one or check out the dimensions
Some convertible car seats require the child to be at least 19 inches long, while others have no minimum height requirement.
Some convertible seats have a maximum height limit of 36 inches, while others only use the fine print below. See your car seat labels or manual.
The FINE PRINT about rear facing height limits: The child's head MUST be at least ONE inch from the top of the car seat. This is true no matter what the height limit on the car seat says. Your child will outgrow her rear facing car seat's height limit when she reaches the height limit number on the side of the seat OR when her head is within one inch of the top of the car seat.
Some convertible car seats have a minimum forward facing height (usually 34 inches), however, your safest bet is to keep the child rear facing until he has outgrown the rear facing limits. Turning your child around before that means less protection for your child during a crash.
The upper height limit ranges from 40-53 inches depending on which seat you choose.
The FINE PRINT about forward facing height limits: No matter what the upper height number is, your child will outgrow his forward facing seat when the top of his ear (the midpoint of his head) reaches the top of the car seat. This holds true for ALL forward facing seats and it protects the head from whiplash.
Which one is easiest to use?
Thanks to the National Highway Traffic Safety Administration's
Ease of Use Ratings
many difficult to use car seat features have been laid to rest. Sometimes, however, ease of use can depend on your own preferences.
Why Rear Face Longer?
Rear facing is safer! Keep your child rear facing until 2 years of age (yes, I said 2 years old) UNLESS he has outgrown the rear facing limits of his convertible car seat.
A recent article published in the professional journal, Pediatrics (2008) shows that children are five times safer riding rear facing from their 1st birthday until their 2nd birthday.
Chances are that your child will outgrow his car seat before then, but keep his risk of injury lower by rear facing him as long as possible.
Which one is Best?
This is probably the number one asked question by new parents. Read more about the
best convertible seats
4 changes you MUST make when switching to Forward Facing
It is EXTREMELY important to make these 4 adjustments to your convertible car seat when you convert it to a forward facing seat.
For each of these please refer to your car seat owner's manual. Again, it's not rocket science, but each item has a very particular placement that WILL make a difference during a crash.
1. Change the angle of the seat to the UPRIGHT POSITION. This usually means moving a plastic "foot" on the bottom of the seat to a new position. Do not just change the angle of the car seat.
2. RE-THREAD the LATCH belt or seat belt through the forward facing belt path on the car seat.
LATCH note: Sometimes this means you'll have to fidget with the LATCH belt and the crotch strap in the car seat. Be particularly careful to keep all the straps clear of each other...look under the padding to be sure you got it right!
3. ADJUST the harness height so that it is at or above the child's shoulders.
4. ATTACH the TOP TETHER to the forward facing LATCH anchor. Now technically, if you're using the seat belt, you may not HAVE to use the top tether, but you absolutely WANT to.
IMPORTANT NOTE: Use your vehicle owner's manual to determine where the top tether anchor is. Many people use cargo tie downs or other spots that seem ok, but are not actually safe for a car seat during a crash.
One more...#5 If possible, move the vehicle seat in front of the child forward or the child's vehicle seat back away from the seat in front of it. However, you need to consider who else is sitting in the car. The goal here is to get everyone as far away from anything they can hit during a crash & many times people hit the interior parts of the car.
What is the next step?
This depends on a few things. Many kids outgrow their convertible seat before they are ready for a booster seat. Here are the factors you will need to consider:
1. child's age
2. child's behavior
3. child's height
4. child's weight
5. vehicle seat belt situation (for example, you MUST have a shoulder belt to use a booster seat.)
6. and sometimes, who else is riding in the car (for example, do all the car seats fit next to each other?)
for switching from either a convertible to a combination seat or from a harnessed seat (meaning a convertible or combination seat) to a booster seat.