A formula for increasing a pattern?

29 times 2 equals 58 cm.

So, try doubling the pattern, and check the pattern measurements against your doll's.
The pattern should be a little bigger than the doll--logical enough, since the clothing must fit over your doll.
clothes ((body)) clothes.
Or try the enlarged pattern on; trace a copy onto paper towels & tape them together for a quick & dirty sizing trial.

Ann in CT