Australia
How Thick Should a Seat Cushion Be? A Foam Thickness Guide in mm
A quick guide to choosing the right foam thickness in mm for chairs, benches, window seats, lounges and daybeds.
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Quick answer: As a guide: 40 to 50 mm for dining chair and bar stool pads, 50 to 75 mm for kitchen benches, 50 to 100 mm for window seats, 100 to 150 mm for outdoor lounge seats and daybeds, and 125 mm or more for deep-seat lounges. Thicker is not always better: on a bench or window seat, too much foam raises the seat height and can make it uncomfortable.
Foam thickness is the decision that most changes how a cushion feels, and it is the one people most often guess. Too thin and you feel the frame; too thick and a bench becomes too high to sit on comfortably. Here is a practical guide in mm.
Thickness by use
| Where it goes | Typical thickness | Why |
|---|---|---|
| Dining chair and bar stool pads | 40 to 50 mm | Adds comfort without changing seat height much. |
| Kitchen benches and banquettes | 50 to 75 mm | Comfortable for a long meal and keeps the table height right. |
| Window seats | 50 to 100 mm | Thicker for lounging, thinner if the sill sits low. |
| Outdoor chairs and lounges | 100 to 150 mm | Fills the frame and supports longer sitting. |
| Daybeds and swing beds | 100 to 150 mm | Good for lying down without feeling like a mattress. |
| Deep-seat lounges | 125 to 200 mm | Plush, sink-in comfort for generous frames. |
Check the seat height
Before choosing, measure from the floor to the top of the seat base, then add the foam thickness. A comfortable dining or bench seat usually finishes around 450 to 480 mm from the floor. If the result is much higher, choose thinner foam.
Thickness isn't the only factor
- Firmness: a thinner, firmer foam can feel more supportive than a thick soft one.
- Wrap: a polyester fibre wrap softens the edges and fills the cover for a fuller look.
- Indoor or outdoor: for uncovered outdoor seating, quick-dry foam drains water and dries quickly, which helps prevent mould.
Foam for Australian orders is made in Australia by our foam partner. You can buy foam on its own, a cover on its own, or a complete cushion: see custom cut foam and covers and replacement foam.
Next step
Measure your seat with our mm measuring guide, then build your cushion on the custom cushions page. Shipping is free anywhere in Australia, and prices are shown in AUD.
Frequently asked questions
What is the standard thickness for a seat cushion?
Most seat cushions are 75 to 125 mm thick. Dining chair pads are thinner, at 40 to 50 mm, and deep-seat lounges can go up to 200 mm.
Is thicker foam more comfortable?
Not always. Thick foam raises the seat height, and a firmer, thinner foam often feels more supportive.
What thickness is best for a window seat?
50 to 100 mm, depending on how high the sill sits and whether you want to lounge on it.
Which foam is best for outdoor cushions?
Quick-dry foam for uncovered areas, because it drains water and dries quickly. Standard high-density foam suits covered areas.
Where is your foam made for Australian orders?
Foam for Australian orders is made in Australia by our foam partner.
