Increasing size in pattern


Hi. I’ve just finished an adorable baby cardigan. A friend saw it and wants one for her baby niece, who is now 15 mo old. My problem is that the pattern’s largest size is for 18 months. I think I want to make a piece for 30 mo, at least. So - how to increase the pattern for the larger size. I’m thinking: see how much each age-size increases in the pattern, and do 2 more increases of this amount to get from 18 mo to 30 mo. Maybe do this by percentage increase at each step.
What do y’all think, would this work? Is there a better way?

This site has a lot of sizing information, this chart is from age 2 but there is another for babies. You can compare the sizing for the largest size your pattern has with the size you wish to make from this chart and see how feasible it may be. Keep in mind the overall increases are not just horizontal and vertical!
This search on ravelry for a toddler size 1- 3 cardigan has 150+ pages with more than 1100 of them free!! You could maybe search for something similar or just use any one of them in the same yarn weight to compare sizing.
Hope this helps


Thank you so much. I thought I had searched all over Ravelry, but I guess I hadn’t. I found the perfect pattern.