baby car seat positioning

Question about baby car seats.?

My twins are nine months old. At the moment they are still in the rearward facing position in the car. At what age, weight, length do you turn the seats into forward facing position. They are still small babies, they weigh 6.5kg to 7kgs and they are 67cm in length. Im sorry for my american friends I don’t understand pounds and inches. If you want to convert please do so. Thank you

I turned my twins around when they were 12 months old and in the USA the weight is generally 20 lbs.

Then I read online how much safer babies are being rear facing so I turned their carseats back around to the rear facing position and I play to keep them that way until they reach the maximum limit for their carseats.

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