substituting yarn or just needle size?

[keelan]

Ok, so I want to knit this dress for my daughter: http://www.freepatterns.com/fp_pdfs/...erswingtop.pdf but the pattern requires a gauge of 20 sts=4 in with size 6 needles using worsted weight. I have this wonderful yarn I want to use but I think it's sport weight because it knits up at 24 sts=4 in on size 10 needles.

If you were me, would you just double the yarn, keep going up needle size or - sigh! - just find a different yarn to use? :(

[FruDart]

What an adorable pattern :D Try this math: Stitces in pattern / gauge in pattern x gauge of you're yarn.
Example: Pattern sais cast on 100 st. Gauge in pattern = 20, gauge of youre yarn = 28
100 / 20 = 5
5 x 28 = 140