You've bought your pillow cover, but, now what?! To help it live its best pillow life possible, I really want to help you easily determine what size inserts you should buy for your pillow covers! It can be a confusing world, with sizing nuances from every manufacturer, knowing what to size up on, how much, etc. I'm so excited to give you my tried and true recommendations!
The one thing you ALWAYS want to do, is size UP on your insert size. Which means that whatever size your pillow cover is, you need your insert to be larger than it! As a general rule, the smaller the size of your pillow cover, the less you have to size up on your insert. And, the larger the size of your pillow cover, the more you are going to want to size up.
FILLING OUT THE COVER
Once you've found the perfectly sized insert, you want to make sure that you are putting it into your pillow cover properly. Otherwise, it is not going to matter how good your insert is!! I can show you how to do that in a few minutes HERE. WARNING: you may have a strong craving for tacos after watching it…
SOFT OR FIRM
Your preference on the softness or firmness of your pillows will also come into play. I’ve built my recommendations based on a mid point, so if you really love a soft, relaxed look, you may want to shave off an inch or two. And do the opposite for firm, but only add an inch or so. I don’t suggest overfilling your pillow covers too much, you will put more stress on the seams and it could stretch out the fabric over time.
This is a huge factor that also comes into play!! I broke down 5 pillow manufacturers' inserts HERE if you’d like to see the results! The bottom line is that every manufacturer fill weights are different, and there is unfortunately no “one size fits all.” You can usually get away with a lower fill weight on smaller sizes, as you really won’t notice it as much. But, as you start getting into bigger sizes, you have to find a trusted manufacturer to use, or order a few sizes to see which one is the best fit.
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SIZE GUIDE - LUMBARS
- Small Lumbar (11”x19-11”x23”): Size up 1” on your insert size, using a 12”x20” and 12”x24” insert respectively. You could get away with 2” more on the longer side, but I wouldn’t go more than that. I've used THIS ONE for 12"x20" and I am a fan of THIS BRAND that also has a 12"x20" size. Check them out for a 12"x24" size as well!!
- Medium Lumbar (14”x22”- 15”x23”): Size up 1-2” on your insert size, a 16”x24” down/feather insert usually works well on these sizes. I use THIS ONE all the time for these sizes. It is slightly bigger than recommended, but it isn't filled as much, so it still works!
- Large Lumbar (13”x34”- 18”x48”): Size up about 2-3” on these, but mainly on the longer side. For example, for a 13”x34” cover, you can use a 14” (sized up 1”) x36” (sized up 2”) insert, HERE. For the large size, I recommend finding a body pillow insert! And if you're looking to save money on these, I have used poly inserts (like THIS ONE), because they help retain the shape a bit better. The longer the measurement, the more you’ll want to size up on it to provide the best overall fill!
SIZE GUIDE - SQUARES (you can find any of these sizes HERE)
Small Square (17”x17” and smaller): Size up 1” for your insert size. For a 17"x17" size cover, use an 18"x18" insert.
Medium Square (18”x18”-20”x20”): Size up 2” for your insert size. For an 18"x18" size cover, use a 20"x20" insert.
Large Square (22”x22”- 24”x24”): Size up 2-3” for your insert size. For a 22"x22" size insert, use a 24"x24" insert. I use THESE all the time for my 22"x22" covers. While I usually wouldn't recommend sizing up this much, the fill isn't has heavy as most manufacturers, so it fills more like a 24"x24" insert. You may have to finesse your insert sizing for 22"-24" square pillow cover sizes, as manufacturer fill weight differences become more noticeable on the larger sizes. I would err on the side of a larger insert, rather than smaller, when choosing inserts for your 24"x24" pillow covers (go up 2-4" depending on your fill preference- soft or firm)!
- Extra Large Square (26"x26" and larger): Size up 3-4" for your insert size
The above guides should really be a fool proof way to plump up your pillows! I've referenced down/feather inserts only, because they have more "give" than firmer polyester or down alternative inserts. While you can still size up on down alternative inserts, I'd lean towards sizing up at a rate of about half of what I've given above.
And, if you ever need a suggestion for a size not covered here, please don’t hesitate to contact me!
P.S. In case you missed it above, I tested 5 manufacturer's pillow inserts to give you the low down on the best bang for your buck! You can read more about it HERE!
Hi Kirsten, you should be fine using a 16″×20″ insert for that size if that’s all you can find! It may be more firm, it may be OK, it seems most lumbar sizes are not too overly filled. It should be a good starting point!
According to the tag, my pillow inserts are 24×24 inches. What size pillow covers / cases would I need? I was about to get 24×24 covers….but now see that, that wouldn’t be correct. But now not sure what size pillow covers I need for my pillows?
Thanks for this excellent guide. I just bought a 14 × 18 lumbar pillow. Would this be considered small or medium? I might have an easier time finding a 16 × 20 insert (rather than a 15 × 19).
I have 2 – 20″ × 20″ throw pillows and needed memory foam inserts; I contacted you asking if a 22″ × 22″ would be better. You emailed me and suggested that since the memory foam was dense that I stay with the 20″ × 20″ which I did. I ordered the AM Aeromax memory foam throw pillow insets from Amazon. I received the inserts today and they are perfect. You have to spread the inserts inside the pillow somewhat but they fill out beautifully almost as if by magic. Thanks for your suggestion. I thought others might benefit from this information.
I have 2 pillows size 20″ × 20″; I want to use shredded memory foam for the inserts. The pillows get a lot of use for my son while he watches TV. Should I get 22″ × 22″ inserts and where can I get this size or will someone have to make the inserts for me? Will you please send an email with your recommendations? Thank You. Doris