When placing buttons and buttonholes, some knitters make the mistake of measuring each placement. The tape measure is of little help in getting accurate placement because knitted fabric stretches and what is 2″ (5) cm one time may not be the same measurement the second time. The trick to placing buttons and buttonholes precisely is counting rows.
Know how many rows you get per inch and you can place buttons and their corresponding buttonholes right where you want them. According to pattern standards the first and last button is usually place 1/2 inch (about 1.25) cm from the top and bottom of the garment. The rest of the buttons are spaced evenly between these two.
I do a dry run, laying out the buttons on the back of the garment because the front area where they will go has not yet been constructed. When placing the top and bottom button I figure out how many rows I am working per inch. For the latest baby sweater I am knitting 9 rows per inch. To find how many rows per 1/2 inch I divide 9 by 2 which equals 4.5 rows. I have a choice of rounding that number up or down. I decided to round it down to 4. Thus, I know 4 rows from the top of the garment and 4 rows up from the bottom of the garment will have buttons.
Next, I lay out the remainder of the buttons between the top and bottom. For this particular baby sweater I only had one more to place. I found the middle distance between the top and bottom by measuring between the two buttons. The total distance was 2.5 inches. To find the half way point, I divided the total by 2 and got 1.25 inches. I multiply the 1.25 inches by my row gauge of 9 and I get 11.25 rows as the middle distance between the top and bottom button. Again, I round down to 11 rows.
Now I know that at four rows I need a buttonhole and button. I knit another 10 rows and on the 11th I make another buttonhole. When I am four rows shy of the top of the garment in goes another buttonhole.
Since buttonhole bands and button bands are usually worked separately the row counting works great. On the buttonband when I come to a row where a button will go I mark that row with either a piece of yarn or a removable stitch marker. When it comes to sewing on the buttons opposite the buttonholes I don’t need to fuss or fiddle around because their placement is already marked.
I hope this information helps make placing buttons and buttonholes a little easier.