While it sounds like a bit of good advie, do not compare your chameleon's weight to others. It's a bad road to go down.
First of all, most "pet" chameleons are very much overfed and overweight, so it's not a great way to start!
You MUST go by the animal's condition, not their weight. Are they thin, bony and dehydrated? Are they fatty, rounded, and swollen? OR can you see the outline of their muscles, and the subtle hint of some pelvic bones and ribs?
You should be able to see their muscles, and their ribs and hips - but they shouldn't be pronounced. Look at the tail base - is it rounded, or can you see the muscle on the sides?
If it's a veiled, look at the meaty part behind the casque - is it swollen, and bulging out, or is it pretty well in the animal's head? Do the sides of his casque curve inward SLIGHTLY, or do they bulge out, convex?
Here's some references: My male veiled, ~7 years old, is 17" long, and weighs 150 grams.
MY 2 year old CB melleri, is 19 inches long, and weighs no more than half a pound - about 230 grams. And he's a big sucker.
They are in excellent health, and have good, but not huge, amounts of fat deposits.
Here are their pictures. Note they are not skinny.
Fat reptiles die sooner. Reptiles cannot deal with fat the way mammals do.
http://www.zorabellarose.com/Chameleonpics/daddyveiled.JPG
https://www.chameleonforums.com/gallery/showimage.php?i=687&c=18