Keeping the straps of your child's car seat at the correct length is critical for your child's safety. If the straps are too tight, they will be uncomfortable; if they are too loose, they will not be secure enough to keep your child safe in the event of an accident. As your child gets older, you will need to adjust the straps on her Graco car seat to fit her growing body.
Locate the long, loose strap at the front and center of the car seat. This is called the harness adjustment strap. Put your finger on the strap and follow it back into the car seat cushion. You will feel a small metal plate, which you can press downward.
Place your child in the car seat. Buckle him into the seat if possible, to get a sense of how far you will need to adjust the straps. If your child is too large for you to buckle the straps, place them over his arms and legs as though you were going to buckle him in, but do not actually secure the straps.
Pull gently on the harness adjustment strap if you wish to tighten the straps. You should be able to fit a single finger between your child and the straps when the straps are adjusted correctly. This will give your child enough room to be comfortable in the seat, but will not put her at risk.
Press down on the metal plate if you wish to lengthen the straps. While pressing the plate, pull gently on both shoulder straps to lengthen them. Once the straps are long enough for you to secure your child, buckle the car seat and gently pull the harness adjustment strap until you can only fit a single finger between the strap and your child.
Although this is a general guideline for Graco car seats, your model may follow different rules. Always check the instructions for your specific car seat.