How do i enlarge a pattern?

I need to increase a sweater size. How the heck do I do that? Thanks 4 any help : )

A lot of it depends on the sweater. If it’s thin yarn and larger needles, you can go up in needle size. If it’s top down, you can keep going until it fits you. What sweater is it, what size do you want it?

oh duh here’s more info: Brand name is Sirdar Denim Sport Aran V-neck Boys Sweater. They use age for sizes: 1-2, 3-4, 5-6, 7-8, 9-10 11-12 yo. Cast on 63 (70, 74, 80, 84, 88) sts. Front and back r ribbed on the side and st st in the center, raglan sleeves w/ full ribbing, ribbed v-neck. I need 2 make it 4 a 12-14 yo.
Let me know if u need more info. pls. Thanks 4 any lite u can shed : )

Not quite enough information, but here goes. It probably has you use a size 8 needle, so you could go up to a 9 and knit the largest size. The larger sizes have a difference of 4 sts between each size on the cast on, so you could add one or two ‘sizes’ by casting on 4 or 8 sts more.

If the boy is actually 12-14 [I][U]years old[/U],[/I] he may be larger than a [B]size[/B] 12-14. You should get his chest measurement or the chest measurement of something that fits him to make sure it’s going to be large enough