How can I make the sleeves of a shrug longer?

I want to knit a nice big shrug, and Ive got a ton of good patterns, but was wondering how I could make it longer and the sleeves longer. All the patterns for the shrugs are just basically saying to cast on like 153 sts. Work in St st until piece measures 44 in. & bind off. Then fold piece in half bringing cast on edge to bound off edge. Then place markers on each side 7 in. below fold for arm holes. Then to seam sides down from marker.
Also, they are all one size fits all & Im a bigger girl and I want it to be roomy.
Thanks, hope someone can help…

Measure the length that you would like from one sleeve end across your back to the other sleeve end. If you want long sleeves, measure from wrist across your back to the other wrist, for example. Then see how many sts per inch your pattern calls for (or haw many sts per inch your gauge swatch is) and multiply sts per inch times your measurement. That will give you the number of sts to cast on and work for the shrug and sleeves.

Usually the measurement from wrist to wrist is about 12" shorter than your height, so that would be the length you’d need to make this kind of shrug. But ‘try on’ a towel if you have one that long, or measure.