A bay window seat is the best reading spot in the house, but it is also the hardest seat to fit. The walls angle out, the corners are not square, and the depth often changes from one end to the other. Here is how to measure one so your cushion fits the first time.
Know your seat shape
- Straight seat: one long rectangle under a flat window. The easiest case: one cushion.
- Angled bay: a straight center section with two side sections set at an angle. This is the most common bay window.
- Curved or bow window: a gentle curve made of several shallow angles.
One cushion or several sections?
For an angled or curved bay, we recommend separate cushions: one for the center and one for each side. Rectangles are easier to fit, sit flatter where the walls change direction, and are easier to lift out and clean. Small gaps at the joints are normal and barely show once pillows are on the seat.
How to measure, step by step
- Width of each section. Measure side to side along the back wall and again along the front edge. Write down both, because on an angled bay the front is usually longer than the back.
- Depth. Measure from the wall to the front edge of the seat in two or three places.
- Height under the sill. Measure from the seat to the bottom of the window frame, so the cushion does not block the window or the latch.
- Make a paper template for any section that is not a clean rectangle. Lay kraft paper on the seat, trace it and measure the template on a flat floor.
- Round down to the nearest half inch for a snug fit between walls.
For each rectangular section, order a custom size cushion: we make them from 8" to 55" wide and up to 150" long. If your seat has an unusual shape, email a photo and your measurements to support@shademart.zendesk.com and we will tell you the best way to cover it before you order. Our general guide on how to measure for custom cushions covers the basics.
How thick?
For a window seat you sit on every day, 2" to 3" is the usual choice. A 4" cushion is plush, but check that it still clears the window sill. More detail: how thick should a bench cushion be.
Which fabric?
A bay window gets a lot of light and often a cat or dog. Pick a fabric for how the seat is used:
- Pets on the seat: anti-scratch crystal velvet. See the best fabric for cats and dogs.
- Reading nook: faux lambswool or Dutch velvet for a soft, warm seat.
- Kids and spills: waterproof chenille or vegan leather, which wipe clean.
Want to see colors first? Order fabric samples for free. Compare all options in our cushion fabric guide.
Made to order
Every cushion is cut and sewn to your measurements in 1–3 business days and ships within 3–7 business days. Browse all custom cushions.
Shop: Window Seat Cushions
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