Kat no. 3 is the vest I worked on during our third Knitathon. The shoulder construction, where you knit in the round while working increases over a single stitch, is a construction I have used for years when making vests for my grandchildren. This construction makes it very easy to adjust size, you just knit until the shoulders have the desired width! The pattern gives instructions for 8 different sizes, but you can very easily make a vest to fit your specific size.

The vest is open at the sides. You can choose between buttons or ties to close it – buttons will close it tightly, while ties will create a more relaxed look, and I will recommend going down a size to emphasize the open, casual look.

 
Sizes
1–2-3 (4-5-6) 7-8

Measurements on finished garment
Width over chest: 39-41-42,5 (49-51,5-56) 61-65 cm
Circumference of body (when closed): 84-90-93 (105-115-124) 137-145 cm
Length: 48-49-49 (51-51-53) 53-54 cm

Fit
I have designed this vest for an oversize fit, but you can choose exactly the fit you prefer. Measurements are given on the finished garment, so you can choose how much ease you want.
It can be tricky to choose the size of a vest, but if you want a fit like the one in the photos, you can take half of your chest circumference and subtract 2-8 cm / 1-3 inches.
Remember, you can always adjust size. Try the neckline/shoulders on as you go and continue the increase until you reach desired width!

Yardage
400-450-550 (650-750-900) 1050-1200 meters DK weight yarn (approximately 212 meters pr. 100 gr).
Please note that yardage is estimated and may vary between knitters!
The sample is knit in undyed Grå Yak from A Knitters World: https://www.aknittersworld.dk/collections/ufarvet-garn/pr...

Suggested needles
3.25 mm circulars, 80 cm for neckline ribbing (using magic loop when needed)
3.75 mm circulars, 80 cm for body (using magic loop when needed)

Gauge
21 stitches x 28 rounds in stockinette stitch on the larger needle = 10 x 10 cm after blocking.

Note: Needle size is just a suggestion. Adjust needle size if needed to obtain gauge!
Pay extra attention to your gauge when working the purl stitches on the wrong side. Many knitters tend to have a looser gauge when purling. If this happens to you, you will have to go down a needle size on the purl side.