Outdoor Pillow Size Guide
Both measurements below are taken across the centre of the pillow, which is how outdoor pillows are conventionally measured. Both sizes are printed on both sides.
The two sizes
| Size | Width | Height | Best for |
|---|---|---|---|
| Square | 18" | 18" | Most patio chairs, outdoor sofas and loveseats |
| Lumbar | 20" | 14" | Back support on deep seats, benches, swings, Adirondack chairs |
Why 18 inches is the square
Eighteen inches is the standard outdoor pillow size, and it is the one size that works almost everywhere. It fits the majority of outdoor furniture without looking either lost or oversized, and it is the size most people picture when they think of a throw pillow. A 16" square disappears on anything larger than a bistro chair; a 20" square overwhelms a dining chair and pushes you forward. Eighteen sits in the middle and stays there.
When to choose the lumbar instead
The 20" x 14" lumbar is not a smaller square, it is a different job. A square on a deep, reclined seat sits too high and pushes your shoulders forward. A lumbar sits in the curve of your lower back, which is why it belongs on Adirondack chairs, rocking chairs, porch swings and deep sectionals. On a bench, which is usually too shallow for a square to sit properly, one lumbar centred is often all you need.
Matching size to furniture
Patio and dining chairs
The 18" square. One per chair.
Outdoor sofas and loveseats
Two 18" squares at the ends. On a three-seat sofa, add a 20" x 14" lumbar in the middle: that is the arrangement that reads as finished.
Large sectionals
Squares along the back, lumbars in the corners where people actually lean. On deep seating the lumbar does more work than an extra square.
Adirondack chairs, rocking chairs and porch swings
The lumbar, every time. These all have deep, reclined seats where a square sits too high to support your back.
Benches
One lumbar centred, or a lumbar at one end with a square at the other.
How many pillows
Odd numbers look relaxed and even numbers look formal. Two matching squares on a loveseat reads as tidy. Two squares with a lumbar between them, in designs that share one colour, reads as styled. Keeping one colour common across a group is what stops a mix from looking accidental.
Mixing the two shapes
A group of pillows that are all the same shape looks flat. Because there is one square and one lumbar, the variation you have to work with is shape rather than size, and that turns out to be the stronger of the two: a rectangle among squares breaks the rhythm more effectively than a slightly bigger square ever does. Put the squares at the back and the lumbar in front.
Frequently asked questions
How are the pillows measured?
Across the centre of the pillow, edge to edge. Because a filled pillow is domed rather than flat, a tape laid over the surface will read slightly larger.
What is the standard outdoor pillow size?
18" x 18". It suits most patio chairs and outdoor sofas and is the safest choice if you are unsure.
What size is a lumbar pillow?
20" x 14". The rectangular shape is designed to sit in the curve of your lower back on a deep seat.
Do the covers come off for washing?
No. Every pillow has a sewn seam closure rather than a zip, which keeps water and grit out of the fill. Spot clean or dry clean the pillow whole.
Can I use an insert of a different size?
These arrive already filled, so there is no insert to swap.