Measuring Guide: Replacing Collapsed DFS-Style Cushions with New Foam Inserts

If your seat cushions have given up the ghost and you’re upgrading to new foam interiors — don’t make the rookie mistake of copying the old saggy filling. Foam behaves differently, and your measurements need to reflect that.

This guide will walk you through how to measure properly — whether you’re replacing old foam or upgrading from feather or fibre cushions.

🔧 Scenario 1: Foam to Foam – A Like-for-Like Swap (Done Right)

✅ Step 1: Measure the Cover, Not the Old Insert

Old foam loses shape. Always measure seam-to-seam on the empty cushion cover.

✅ Step 2: Add ½” (1.5cm) to the Front-to-Back Measurement

This helps the foam fill out the cover without leaving dips or gaps.

✅ Step 3: Account for the Crown (Not Just the Border)

That front panel or side boxing might measure 12.5 cm (5″), but your cushion needs to look like 15 cm (6″).
Achieve this with:

  • 15 cm foam for full height
    or
  • 12.5 cm foam plus 12oz Dacron wrap top and bottom

🪶 Scenario 2: Feather or Fibre to Foam – Read This Before You Order

Switching from feather or fibre to foam? Sensible move — foam gives structure, lasts longer, and needs less fluffing. But there are some trade-offs to be aware of:

⚠️ 1. The Look Will Change

Feather and fibre cushions tend to have a soft, domed look with rounded edges. Foam gives a more defined, boxy shape.
👉 You may not be able to fully replicate that “puffed-up” look with solid foam alone.

For a closer match to the original feel:

  • We recommend Foam Core cushions with a fibre or feather wrap
  • Or go for foam with a Dacron wrap to soften the edges and crown the top

⚠️ 2. Feather/Fibre Cushions Are More Malleable

Feather and fibre cushions can squash into tight spaces — foam can’t. If you’re working with a fixed space (like between the arms of a sofa), this matters.

👉 Some manufacturers deliberately make feather/fibre cushion covers wider than the space they sit in.

Check this before ordering foam:

  • Measure the total width of all covers side by side
  • Measure the internal width between the sofa arms
    If the covers are wider than the space, you’ve got two choices:
  • Reduce the cushion width to fit
  • Increase the foam thickness to maintain the plump look

🛠️ Final Advice:

A well-measured, well-fitted foam insert will outlast and outperform your old fill — just don’t expect it to behave the same way if your changing the filling medium.

🧾 Cushion Fill Comparison Table

Fill TypeFeel & ComfortLook & ShapeMaintenance NeedsLifespanBest For
FoamFirm, supportiveStructured, boxyLow (no plumping needed)Long-lastingDaily-use sofas, firmer seating, no-fuss users
Foam + DacronMedium-firm with a softer surfaceSlightly rounded edgesVery lowLong-lastingA comfy look without sagging
Foam Core FibreMedium support, soft wrapFull with some giveOccasional plumpingExcellent balanceLooks like fibre, behaves like foam
FibreSoft, lightweightPuffy, rounded, casualNeeds daily plumpingMediumGuest rooms, light use
FeatherPlush, luxurious, sink-in feelDome-shaped, relaxedDaily plumping essentialMediumTraditional look, comfy lounging
Feather Core FoamSoft wrap + firm centreSoft edges with supportLow to mediumLong-lastingBest of both worlds

👇 Quick Tips:

  • Go Foam if you want structure, support, and low maintenance.
  • Foam Core + Fibre or Feather Wrap if you want the “look” of fibre or feather without the faff.
  • Stay Fibre/Feather if you’re after that soft, slouchy look — but be ready to fluff those cushions every day like they owe you rent.