Getting the Size & Proportion
Right the First Time
A cushion can measure fine on paper and still feel wrong. Here's how depth balances thickness, when finished height makes your feet miss the floor, and how a long seat is often better cut into blocks.
Depth vs Thickness: The Proportion
Get these two in balance and the cushion looks right and sits right.
Depth up to 500mm
Keep the thickness at 75mm or less. Much thicker and a shallow seat looks bulky and lopsided.
Depth 500–800mm
Step the thickness up gently. You have room for a fuller cushion without it dominating the seat.
Depth 800mm+ = daybed
People lie on a daybed, so go 100mm and thicker. The 75mm rule no longer applies.
Proportion beats preference
When in doubt, match the thickness to the depth. A shallow cushion that's too thick feels like a slab; a deep one that's too thin feels flimsy. Balance is the practical guide.
The Height Red Line
What matters is the seat your feet actually meet — not just the cushion.
Keep finished height under 550mm
Finished height is the seat base plus the cushion. Above about 550mm most people can't comfortably get their feet flat on the floor.
- Base already 500mm high? Cushion at 50mm.
- Need extra cushion? Lower the base or slim the cushion — don't stack it higher.
Daybeds skip the rule
If the cushion is so deep you lie on it, nobody sits with feet on the floor. A daybed can be thick and luxurious without worrying about the 550mm ceiling.
- Depth 800mm or more = daybed.
- Comfort is the goal, not foot clearance.
Long Seat? Split It Into Blocks
A stretch of seat that runs a few metres is usually better as a few cushions.
Easier to live with
Blocks are lighter to lift, easier to wash and turn, and far more manageable around a sofa or window seat.
- Handle and rotate without wrestling one huge cushion.
- Wash in a normal machine when each block is a sensible size.
Anything around 1.5m and up
If one cushion is hard to lift or wash, split it. Each block is measured and ordered on its own, and the seams line up neatly.
- Stain or tear one block? Clean or repair just that one.
- No need to replace the whole seat.
Split and measure each block separately
Don't eyeball the total length and divide it. Measure each block edge to edge, seam to seam, and enter each one as its own cushion. A little extra care here gives you perfectly matching pieces.
Common Mistakes to Avoid
These are the proportion and sizing traps we see most.
Thick cushion on a shallow seat
Depth under 500mm and thickness over 75mm looks bulky and uncomfortable to sit through.
Forgetting the finished height
Base plus cushion over 550mm puts your feet short of the floor, even if the cushion itself feels great.
Making a long seat as one giant cushion
It's heavy, hard to wash, and a single stain or tear means redoing the whole thing. Split it.
Measuring the foam, not the cover
Foam sags and gives an unreliable number. Measure the cover seam to seam, or the frame inside to inside.
Rounding too much
Give us the most precise number you can — we handle the seam allowance. Bigger is always the safer side.
Questions
Straight answers.
How thick should my cushion be?
If the cushion is up to 500mm deep, keep the thickness at 75mm or less so the proportion stays balanced. Deep daybeds (800mm or more) are a different story — go 100mm and thicker.
What if my feet won't reach the floor?
Keep the finished height under about 550mm. Seat base plus cushion is what your feet feel. If a 500mm base takes a 50mm cushion, that's the sweet spot; lower the base or slim the cushion instead of stacking it higher.
Should I split a long cushion into blocks?
For long seats (roughly 1.5m and up), yes. Blocks are easier to lift and wash, and if one gets dirty or torn you clean or repair just that block instead of replacing the whole thing.
Do I measure the foam or the cover?
Measure the cover seam to seam, or the frame inside to inside. Foam sags and gives an unreliable number.
Can I get a fabric sample first?
Yes — free fabric samples are shipped to your door, so you can feel the fabric before you order.
I'm still not sure — can you help?
Absolutely. Send us a photo and we'll help you measure and even preview your fabric. This isn't rocket science — we're here.
Got the proportions sorted?
Enter your measurements in the designer and we'll cut & sew a cover that fits and sits right.
Start Customising