Types of Mattress Foam
There are three primary types of foam used in mattresses, each with distinct characteristics.
Memory Foam
- Properties: Contours to the body, provides pressure relief, retains heat
- Best For: Side sleepers, people with joint pain, motion isolation
- Variations:
- Traditional Memory Foam: Deep contouring but retains heat
- Gel-Infused Memory Foam: Cooler than traditional foam
- Open-Cell Memory Foam: More breathable, less heat retention
Polyurethane Foam (Polyfoam)
- Properties: Bouncy, budget-friendly, less contouring than memory foam
- Best For: Budget mattresses, transition layers, temporary use
- Variations:
- Low-Density Polyfoam: Soft, breaks down quickly
- High-Density Polyfoam: More durable, used in support cores
Latex Foam
- Properties: Naturally responsive, durable, cooler than memory foam
- Best For: Eco-conscious buyers, hot sleepers, combination sleepers
- Variations:
- Dunlop Latex: Denser, firmer, used in support layers
- Talalay Latex: Softer, more breathable, used in comfort layers
2. Understanding Foam Density
Foam density is measured in pounds per cubic foot (PCF) and directly affects durability, support, and performance.
Foam Density Scale
| Density (PCF) | Foam Type | Durability | Feel | Best For |
|---|---|---|---|---|
| 1.5 – 2.5 PCF | Low-Density Polyfoam | Low | Soft, less support | Budget mattresses, guest beds |
| 3.0 – 4.0 PCF | Medium-Density Memory Foam | Moderate | Balanced contouring | Most sleepers, value-conscious buyers |
| 4.5 + PCF | High-Density Memory Foam | High | Deep contouring, slow response | Heavy sleepers, durability seekers |
| 4.0 – 5.5 PCF | Latex Foam | Very High | Responsive, durable | Eco-friendly, hot sleepers |
How Density Affects Sleep
- Higher Density (4+ PCF) → More durable, supportive, but can feel too firm and retain heat
- Medium Density (3-4 PCF) → Good balance of contouring and durability
- Lower Density (< 3 PCF) → Softer, less durable, best for temporary or guest use
Tip: If you’re looking for a memory foam mattress that will last 7+ years, choose a foam layer with at least 4 PCF density.
3. Understanding ILD (Indentation Load Deflection)
ILD measures foam firmness by determining how much pressure is needed to compress the foam by 25% of its thickness.
ILD Ratings and Firmness Scale
| ILD Rating | Firmness Level | Feel | Best For |
|---|---|---|---|
| 8-12 ILD | Very Soft | Plush, deep sinkage | Lightweight side sleepers, pressure relief |
| 13-20 ILD | Medium-Soft | Contouring, some support | Side sleepers, combination sleepers |
| 21-30 ILD | Medium-Firm | Balanced support | Back sleepers, most sleepers |
| 31+ ILD | Firm | Little give, maximum support | Stomach sleepers, heavier individuals |
How ILD Affects Sleep
- Lower ILD (Soft Foam, < 15 ILD) → Allows for deeper pressure relief but may lack support
- Medium ILD (Balanced Feel, 15-25 ILD) → Offers support while maintaining comfort
- Higher ILD (Firm Foam, 25+ ILD) → Provides strong support but can feel too stiff
Example: A plush memory foam mattress may have a comfort layer of 12 ILD, while a support layer may have a firm 30 ILD base for stability.
4. Foam Density vs. ILD: Which Matters More?
- For durability → Density matters more. High-density foams last longer.
- For comfort → ILD matters more. Low ILD = Softer feel, High ILD = Firmer feel.
- For pressure relief → Both density and ILD must be balanced.
Example Mattress Composition for Different Sleepers
| Sleeper Type | Comfort Layer ILD | Support Layer ILD | Density |
|---|---|---|---|
| Side Sleeper | 12-18 ILD | 25+ ILD | 3-5 PCF |
| Back Sleeper | 18-25 ILD | 30+ ILD | 4-6 PCF |
| Stomach Sleeper | 25+ ILD | 35+ ILD | 5+ PCF |
5. Choosing the Right Foam for Your Needs
Best for Soft, Plush Feel & Pressure Relief
- Density: 3-4 PCF (Memory Foam)
- ILD: 8-15 (Soft Foam)
- Best for: Side sleepers, lightweight individuals
Best for Balanced Support & Comfort
- Density: 4-5 PCF (Memory Foam or Latex)
- ILD: 15-25 (Medium Foam)
- Best for: Combination sleepers, back sleepers
Best for Firm Support & Durability
- Density: 5+ PCF (Memory Foam or Dunlop Latex)
- ILD: 25+ (Firm Foam)
- Best for: Stomach sleepers, heavier individuals
6. Final Thoughts
- Density affects durability and support. Higher density = longer lifespan.
- ILD determines firmness and comfort. Lower ILD = softer, higher ILD = firmer.
- Memory foam provides deep contouring but retains heat.
- Latex is more responsive and breathable but costs more.
- Polyfoam is budget-friendly but less durable.
For most sleepers, a medium-density foam (4-5 PCF) with a medium ILD (15-25) offers a balanced mix of support, comfort, and durability.