Reading A Percentile Chart (#2)

This is a follow-up post to Part 1 :)

Tim's Percentile Chart

We are referencing Tim's percentile chart (above). Let's zero in on Tim's weight.

I have plugged in 3 points to use as Tim's weight and will explain each one :)

To begin, I went to the line above the word birth.

Don't get confused, we are using pounds (lb), not kilograms, but it is the same method for both. 

The first point is Tim's weight at birth.
I looked for the correct number of pounds ~7.5 pounds. 

Second point is Tim's weight at 3 months (Point 2) ~8 pounds.

Lastly, I found Tim's weight at the age of 6 months (point 3) ~10 pounds. Follow the line to the right, not the left.  
 

*It does happen that numbers fall between percentile marks, try to judge which percent your child is closest to (please see the examples).  


Reading Tim's Weight Chart - Percents
*At birthTim weighs: 7.5 pounds (~3.4 kg) - See Number 1 in Weight Area 

Tim's weight landed him near the 50 percent mark.

When Tim's weight is compared to other babies his age,  Tim weighs the same or more than 50 percent of boys at birth and 50 percent of boys weigh less than he does.

~Let's look at that a little closer:

Tim landed closest to the 50% mark and is the same weight or heavier (*same or more) than 50 percent of babies. 50 percent of babies weigh less than Tim (Since he is at the 50 percent mark, any child weighing less than that, weighs less than Tim). 

*The term same or more is used so that it fits all numbers. For example, an infant is not at exactly at the 50 percent mark, but at the 54 percent mark, it can be difficult to get to such a precise percent. Getting to the closest percentile is what matters, not hitting the exact number. That infant would be closer to 50 percent than the next percent which is 75 percent.

*At 3 months Tim weighs 18 pounds (~8 kg) - See Number 2 in Weight Area

Tim's weight has landed him above the 95th percentile.

When his weight is compared to other 3 month olds, Tim weighs the same or more than 95 percent of boys at this age. He weighs more than 95 percent of boys. 

*At 6 monthsTim weight is 22 pounds (10 kg) - See Number 3 in Weight Area

Tim's weight has landed him above the 95th percentile.

When his weight is compared to other 6 month olds, Tim weighs the same or more than 95 percent of boys at this age. 95 percent of boys weigh less than he does.


As Tim continues to visit his doctor regularly, his doctor will continue to reference his growth chart to see trends in his growth and will note any changes. Ideally, his doctor wants to see the plotted points increase over time. This tool should be used as a way to see your child's growth, not to compare your child to other children. Every child is different. As long as you and your doctor have discussed your child's growth and deem it healthy, don't get too hung up on the numbers. It's just a tool. 

Next up, Length.

Take care,
-km