Updated October 2025 | by The Cushion Guys
If your sofa cushions feel flat, sagging or uncomfortable, replacing the cushion interiors can completely transform how your furniture looks and feels. In many cases, tired sofa foam is the reason seating loses support long before the sofa itself needs replacing.
Whether you are replacing worn inserts, upgrading to firmer support or restoring softness to older seating, accurate measuring is the most important step when ordering replacement cushion foam.
At The Cushion Guys, we specialise in foam cut to size and made-to-measure sofa cushion refills, helping homeowners across the UK restore comfort, support and shape to tired seating.
This guide explains exactly how to measure sofa cushions for refill correctly, including how to measure cushion covers, choose the right foam grade and avoid the most common sizing mistakes.
One of the biggest mistakes people make when ordering replacement sofa foam is measuring the old foam inserts instead of the cushion covers.
Over time, foam naturally compresses, warps and loses shape. Measuring old inserts often leads to replacement cushions that feel loose, uneven or incorrectly sized.
Correct measuring helps ensure:
For the most accurate results, always measure the empty cushion cover rather than the old foam itself.
Before measuring your sofa cushions, prepare the following:
A rigid tape measure is usually more accurate than soft fabric measuring tapes because it stays straighter across wider cushions.
For best results:
Carefully unzip your cushion covers and remove the old foam or fibre inserts completely.
This allows you to measure the true shape and dimensions of the cushion cover without distorted or compressed fillings affecting the measurements.
Place the empty cushion cover on a clean, flat surface.
Smooth the cover gently using your hands, but do not stretch the fabric tightly. Pulling the cover can distort the dimensions and result in oversized foam.
Measure from the left seam to the right seam across the front of the cushion cover.
This is your width measurement.
Measure from the front seam to the back seam.
This gives you the cushion depth.
Zip the cushion cover closed and stand it sideways naturally.
Measure the full height of the side panel to determine the cushion thickness.
| Measurement | Description | Example Size |
|---|---|---|
| A | Width | 60cm |
| B | Depth | 55cm |
| C | Thickness | 10cm |
Your replacement foam would therefore be ordered as:
60cm x 55cm x 10cm
Not all sofa cushions are simple rectangles. Many sofas use T-shape cushions, curved cushions or angled seating layouts that require more detailed measuring.
If your cushions have unusual shapes:
At The Cushion Guys, we regularly manufacture custom foam cushions for:
Explore our T-shape sofa cushion foam and custom foam services.
Old sofa foam often becomes compressed, misshapen or uneven through years of use.
Never rely on warped foam measurements when ordering replacements.
If your old foam has badly distorted:
Accurate measurements help ensure your replacement cushion inserts fit neatly without loose corners or overfilled pressure points.
Choosing the correct foam grade is just as important as getting the measurements right.
Different foam types create very different seating experiences depending on the level of support, comfort and durability you prefer.
Soft foam creates a relaxed and sink-in seating feel. It is often used for back cushions or occasional seating where softness is prioritised over structure.
Medium foam is one of the most popular options for everyday seating. It provides balanced comfort and support while still maintaining good shape retention.
Firm foam provides stronger support and is ideal for larger sofas, deep seating and high-use family furniture.
Memory foam toppers can be added to standard foam inserts to create enhanced pressure relief and softer contouring comfort.
Explore our full foam cut to size service for more information on foam grades and support options.
| Foam Type | Comfort Feel | Best For | Support Level |
|---|---|---|---|
| Soft Foam | Relaxed and plush | Back cushions and occasional seating | Soft |
| Medium Foam | Balanced comfort | Everyday sofas and family seating | Medium |
| Firm Foam | Structured and supportive | Deep sofas and high-use seating | Firm |
| Memory Foam | Pressure-relieving comfort | Luxury seating and support upgrades | Medium-Firm |
We strongly recommend adding a Dacron fibre wrap around new foam inserts.
Dacron helps:
Adding Dacron is one of the easiest ways to make replacement sofa cushions look and feel more luxurious.
Incorrect measurements are one of the biggest causes of poor-fitting replacement cushions.
Common mistakes include:
Taking careful and accurate measurements helps avoid unnecessary fitting problems later.
High-quality sofa cushion foam can typically last between five and ten years depending on:
High-density foam generally lasts longer because it retains shape and support more effectively over time.
Once your replacement cushion foam arrives, a few simple maintenance habits can help maximise lifespan and comfort.
Need replacement covers as well? Browse our made-to-measure cushion covers.
You may also find these guides useful:
At The Cushion Guys, we specialise in handmade made-to-measure cushion refills and upholstery foam cut precisely to your dimensions.
Every cushion insert is manufactured in the UK using carefully selected foam grades designed for comfort, durability and long-term support.
Always measure the empty cushion cover rather than the old foam insert. Foam naturally compresses over time and may no longer reflect the correct dimensions.
Medium foam is the most popular choice for everyday sofas because it balances comfort and support. Firm foam is ideal for deeper seating and high-use family sofas.
Yes. We manufacture custom foam inserts for T-shape cushions, curved cushions, bay window seating, campervans and bespoke furniture projects.
Accurate measurements are extremely important for achieving a clean fit and proper support. Always measure seam to seam and round up to the nearest half centimetre.
Yes. Many customers order replacement foam inserts to fit inside their existing cushion covers, helping refresh comfort without replacing the entire sofa.
Whether you need replacement sofa cushion foam, supportive seat inserts or custom-cut upholstery foam for bespoke furniture, The Cushion Guys make it easy to restore comfort and support to tired seating.
Browse our foam cushions cut to size or speak to our experienced team for help choosing the right foam for your sofa.
Choose your filling and create handmade made-to-measure cushions tailored to your comfort, style and space.
