Gauge confusion!

I need help!

I bought some yarn (Berrocco Nostalgia) for a summer sweater that is knit front and back then sewn. I am a really new knitter, and my tension is uneven on long rows of knit and purl. I found a pattern that I want to knit, I have plenty of yarn and it is in the round, but I’m so not sure about gauge.

The old sweater called for size 7 needles and I was right on gauge. The new pattern calls for size 6 and 3 needles. So…what do I do? I have been thinking and thinking, trying to reason this out, but I just don’t know what to do.

I wouldn’t really worry but I so want to use up this yarn and this project seem like a good fit.

You can do a faux in-the-round swatch.

Using a dpn or circular needle, knit across your stitches, but instead of purling back, slide the stitches to the other end of the needle. Leave a long, loose strand across the back and knit the row again. Keep doing this until you have enough to measure your gauge for in-the-round.