My sister-in-law asked for legwarmers for Christmas, and was very particular about what kind. They needed to be in Aran yarn, with some cabling but not too much, and loose enough to be a little bit slouchy around the leg, but again not too much. Together we chose some lovely Texere Yarns Airedale Aran in Herb (colourway 1222), and I got knitting!
The legwarmers used almost exactly 3 balls of the Airedale Aran. I didn’t do a gauge swatch, because with legs and feet it’s simpler to check for diameter by just starting then trying it on the nearest passing leg (your own if it’s the appropriate size). If you want to make longer legwarmers, or adapt to make them slouchier, you will need extra yarn.
The pattern starts at the knee, incorporating decreases between the cable sections to fit to a shapely calf while still remaining slouchy.
They are designed to fit an average sized adult woman.