Chairs look best with decorative pillows that are similar in width as the width of the seat.
To get an ideal pillow size range, measure how wide the seat of your chair is, and then either subtract 4 inches to get the minimum width, or add 4 inches to get the maximum width.
Minimum pillow width = seat width - 4
Maximum pillow width = seat width + 4
As an example, this chair below has a seat width of 22", so we want a pillow that's somewhere between 18" to 26" wide.
The pillow shown is size 13x19 so it's width is right within the 18" to 26" range and it looks pretty good. We could stand to go larger if we wanted to fill up more of the seat width, perhaps a 13x21 or 13x25 lumbar. Anything too much smaller than the 13x19 though would look disproportionate.
You might be wondering, if the seat width is 22", why would you recommend a pillow that's wider than that?
The reason is because once a pillow cover has been filled with an insert, it's dimensions change. About 4 inches of it's width measurement when laid flat, get used up for the depth. That's why we can go up to 4 inches larger, because a pillow cover that measures 26" when laid flat, transforms into a stuffed pillow that has some depth and measures about 22" wide.
That said, the higher end of the width range works best for lumbar pillows. For comfortability, if you choose a square shaped pillow, we recommend sticking to the middle to lower end of the range. Although a 26x26 square pillow would technically fit on the above 22"wide chair, that size would be too bulky and would eat up a lot of the seat depth.
It may be difficult to find readymade pillows that are just the right size for your chairs. Luckily most of Regular Collection pillows can be custom made in your ideal dimensions. Feel free to contact us anytime for a quote or customized size recommendation.