How to Measure Foam for Cushions
Ordering foam cut to size is one of the most practical ways to get a perfect fit for your sofa, caravan, boat, window seat, or any other project. But if you've never done it before, it can feel a little daunting. This step-by-step guide makes it simple.
Step 1: Measure Your Space Accurately
The most important part of ordering custom foam is getting your measurements right. Use a tape measure and measure in centimetres. You'll need three dimensions:
- Length — the longest side of the foam piece
- Width — the shorter side
- Thickness (Depth) — how deep the foam needs to be
Measure the space the foam will sit in, not the old foam — old foam may have compressed or shrunk over time. If you're replacing a sofa cushion, measure the cushion cover from seam to seam on the inside.
Step 2: Consider a Slight Overcut for Cushion Covers
If your foam will go inside a cushion cover, you may want to order it 1–2cm larger than the cover's internal dimensions. This gives the cushion a fuller, plumper look and prevents the foam from shifting inside the cover. For hard-edged applications like caravans or boat seating, order to exact dimensions.
Step 3: Choose Your Foam Type
Different projects call for different foam types. Here's a quick guide:
- Sofa seat cushions: High-density foam (40–50 kg/m³), medium to firm
- Sofa back cushions: Medium-density foam, soft to medium
- Caravan & boat seating: High-density foam for durability in confined spaces
- Window seats & benches: High-density foam, firm
- Headboards & decorative panels: Medium-density foam, soft
- DIY projects & packaging: Low to medium density depending on use
Step 4: Choose Your Firmness
Firmness is separate from density (see our foam density guide for a full explanation). In simple terms:
- Soft: Comfortable for lounging, back cushions, and low-use seating
- Medium: Everyday sofa seating — the most popular choice
- Firm: High-use seating, dining chairs, caravans, and anyone needing extra support
Step 5: Place Your Order
Once you have your measurements and foam type, you're ready to order. At FoamNest, you can enter your exact dimensions and choose your foam type directly on the product page. Every piece is cut to order and dispatched quickly across the UK.
Tips for a Perfect Result
- Double-check your measurements before ordering — measure twice, order once
- For irregular shapes (L-shaped seats, curved edges), contact us before ordering
- If replacing multiple cushions, measure each one individually — they're often slightly different sizes
- Keep a note of your dimensions for future reorders
Order Your Custom Foam Today
FoamNest supplies precision-cut foam to homes, upholsterers, caravan owners, and DIY enthusiasts across the UK. Simply enter your dimensions, and we'll cut and deliver your foam straight to your door.
Ready to order?
- Foam cut to size calculator
- Replacement sofa cushion foam
- Caravan & campervan foam
- Foam mattress cut to size
Still deciding on firmness? See what foam density you need.