Converting yarns

I need help with what is more than likely a common problem. I have a pattern that calls for Rowan Biggy Print yarn (33yds; 100 gr.) with a gauge of 6 sts x 8 rows=4"x4" using #19 US needles. I would like to substitute for another yarn that is less expensive which has a guage of 8 sts/4" on US #13 and is 43 yds per 50 gr. ball. The pattern calls for 8 balls of the Rowan yarn. How do I convert this properly??? :wall: Thanks so much for help as I want to make this garment for a Christmas gift and need to start it ASAP!

Susan the Math Challenged Soprano/Artist is NC !!!

I think this is what you’re looking for. If you need help reworking the pattern for the new gauge, knittingfiend has a calculator for that too. (You should be able to link to the calculator page from the above link.) :thumbsup: