Knitting – weird sizes

I have made a couple of things from this pattern booklet before and never noticed the weird sizing. I made a cardigan that I have made previously in a smaller size, this time in 2-3 years. But it came out tiny! I also made a jumper size 12-18 months which came out bigger than the cardigan!

The cardigan:

The Jumper:

Compared to each other and the rainbow flower cardigan:

So this cardigan was too small for my granddaughter, but she loved the rainbow one. I knew someone else with a younger toddler, so gave this cardigan to them. I have bought some more of the wool, so will make another a size bigger!!