The Cutting Table · a question, worked through
What is 32 kg/m³ foam in lb/ft³, and what's its ILD?
Two unit systems, one foam. Here's the conversion, the firmness number, and the one thing nobody can hand you: a lab certificate.
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The quick answer
32 kg/m³ foam is about 2.0 lb/ft³, so it clears the common 1.8 lb/ft³ high-density requirement. The workshop's seat foam is high-resilience cold foam, described as T32 with an ILD of about 42, which sits in the firm category and holds adults without sinking through. There's no official lab ILD certificate, and ILD can vary slightly by batch.
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Key facts
- 32 kg/m³ is about 2.0 lb/ft³.
- That meets a 1.8 lb/ft³ high-density requirement.
- Seat foam is high-resilience (HR) cold foam, T32 density, also called 32 DNS.
- The stated ILD is 42, in the firm category; no official ILD certificate is issued.
- ILD can vary slightly from batch to batch.
- Floor and modular sofa mattresses use T28 foam, also at ILD 42.
- Firm seat cushions can be made 6 in (15 cm) thick on request.
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"What's 32 kg/m³ in pounds?"
About 2.0 lb/ft³. The math, partner: divide kg/m³ by 16.02. So 32 ÷ 16.02 = 2.0, which clears the 1.8 lb/ft³ high-density line buyers ask about for seat foam. The density conversion Pattern has the full table, and the glossary entry on foam density explains the unit.
"And the ILD?"
Stated as 42. ILD measures how hard the foam pushes back when pressed, and 42 lands in the firm category. The workshop has no official lab ILD certificate to quote, and ILD can drift slightly between batches.
One buyer in the US asked for ILD 44 or firmer. The shop didn't promise 44; it placed its foam in the firm category and left it there. That's the honest answer. The density vs firmness Pattern explains why the two numbers move separately.
"Is it HR foam? Can it be 6 inches?"
Yes on both. It's high-resilience cold foam, described as T32 density, also called 32 DNS foam; bench cushions wrap it in Dacron. Firm seat cushions can be made 6 in (15 cm) thick on request. What thickness is your bench cushion now? Run the numbers in the foam firmness finder or browse bench cushions.
The two foams, in both units
| Foam | Density | In lb/ft³ | ILD | Used in |
|---|---|---|---|---|
| T32 HR cold foam | 32 kg/m³ | about 2.0 | 42 | Bench and seat cushions |
| T28 foam | 28 kg/m³ | about 1.75 | 42 | Floor and modular sofa mattresses |
A foam's ILD is a stated figure, not a lab promise: 32-density HR seat foam is quoted at ILD 42, and it can vary slightly from batch to batch.
Nate
Buyer questions
- A common question
Do you have high-density foam, 1.8 lb or more and ILD 44 or firmer, 6 in thick, so adults won't sink through?
The workshop's answerYes. The foam is about 2.0 lb/ft³ (32 kg/m³), so it meets the 1.8 lb requirement, and it's firm enough that adults don't sink through. There's no official ILD rating to quote, but it's in the firm category and used for all the seating. A 25 x 78 x 6 in (64 x 198 x 15 cm) cushion was quoted.
- A common question
What type and density of foam do you use?
The workshop's answerHigh-resilience cold foam described as T32 density with ILD 42, also called 32 DNS foam. It gives firm but comfortable support and keeps its shape under daily use.
- A common question
What goes inside the bench cushions and the modular sofa?
The workshop's answerBench cushions use 32-density high-density foam wrapped in Dacron. On the modular sofa, the inner cushions are foam as well, the support bars are steel and the upholstery fabric is 100% polyester.
- A common question
What density foam is in the floor sofa?
The workshop's answerFloor sofa seats use 28-density foam, about 1.75 lb/ft³ (28 kg/m³), a medium-hard high-density foam, sometimes quoted as 28-32, which the shop says lasts for years without collapsing.
Questions buyers ask next
Is higher-density foam always firmer?
No. Density (kg/m³ or lb/ft³) is how much foam is packed into a given volume; firmness is measured as ILD. The workshop's T28 and T32 foams differ in density but are both stated at ILD 42.
Can I get foam firmer than ILD 42?
When a buyer asked for ILD 44 or firmer, the shop placed its foam in the firm category rather than confirming 44. With no lab certificate, treat 42 as the stated figure, not a guaranteed number.
How do I convert other foam densities?
Divide kg/m³ by 16.02 to get lb/ft³, or multiply lb/ft³ by 16.02 to go back. So 28 kg/m³ is about 1.75 lb/ft³, and 1.8 lb/ft³ is about 29 kg/m³.
