Getting the mattress size right is one of the most important decisions in a van conversion. A standard mattress is cheaper and easier to replace than a custom one. But it will not fit every layout.
This guide covers UK standard sizes, which van layouts they suit, and when to go custom.
| Size Name | Dimensions (cm) | Width | Length |
|---|---|---|---|
| Small Single | 75 x 190 | 75cm | 190cm |
| Single | 90 x 190 | 90cm | 190cm |
| Small Double | 120 x 190 | 120cm | 190cm |
| Double | 135 x 190 | 135cm | 190cm |
| King Size | 150 x 200 | 150cm | 200cm |
| Super King | 180 x 200 | 180cm | 200cm |
Note: These are UK standard sizes. European van mattresses often use different dimensions (e.g., 140 x 200cm for a continental double).
Which Size Fits Which Van
Transverse Bed (Across the Van)
A transverse bed uses the van's width as the mattress width.
| Van | Internal Width | Fits Standard Size |
|---|---|---|
| VW Transporter SWB | 1.70m | Small double (120cm) or custom |
| Transit Custom | 1.78m | Small double (120cm) |
| Renault Trafic | 1.96m | Double (135cm) or small double (120cm) with corridor |
| Ford Transit LWB | 1.78m | Double (135cm) if no corridor |
| Citroen Relay | 1.87m | Double (135cm) |
Transverse bed length: The bed depth is limited by the van's load length minus kitchen/setback. Typical transverse bed depths: 60-75cm.
Longitudinal Bed (Along the Van)
A longitudinal bed uses the van's length as the mattress length.
| Van | Internal Load Length | Fits Standard Size |
|---|---|---|
| SWB (Trafic L1, Transit Custom) | 2.53-2.55m | Single 190cm + extra storage |
| MWB (Trafic L2, Transit Custom LWB) | 2.80-2.93m | Single 190cm + kitchen |
| LWB (Transit, Sprinter) | 3.05-3.30m | Single 190cm + spare space |
| XLWB (Relay, Ducato) | 3.50-3.73m | King 200cm + wardrobe |
Longitudinal bed width: Limited by the van width minus a corridor. Typical widths: 60-75cm (single/small single).
Best Standard Size for Each Layout
Transverse bed for couples: Small double (120 x 190cm) in most vans. The 120cm width is narrow (equivalent to a UK small double) but works for closer-quartered sleeping. The 190cm length is usually fine because the bed runs across the van, and most people are shorter than 190cm in shoulder width.
Transverse bed for solo: Single (90 x 190cm) is comfortable and leaves more space for kitchen.
Longitudinal bed for couples: Not practical with standard sizes. A longitudinal double bed would need to be at least 135cm wide, which leaves no corridor in most vans. Custom narrow double or use a transverse layout.
Longitudinal bed for solo: Single (90 x 190cm) fits perfectly in most LWB or XLWB vans with a corridor of 40-50cm.
Drop-down bed: Most drop-down mechanisms use custom sizes. Standard widths do not fit the mechanism brackets that mount to the roof crossmembers.
When to Use a Standard Mattress
- Budget builds: A standard IKEA mattress (£50-150) is 1/3 the cost of custom
- Easy replacement: Standard mattress toppers, sheets, and protectors are widely available
- Resale: Future buyers can replace the mattress easily
When to Go Custom
- Transverse bed in a narrow van: A 1.70m wide Transporter cannot fit a 190cm long standard mattress transversely. You need a custom 160-170cm mattress.
- Raised bed / French bed: Unusual dimensions due to wheel arch cutouts
- Drop-down bed: Standard sizes rarely match the structural mounting constraints
- Unique layout: Any layout that does not use standard 90cm, 120cm, or 135cm widths
Custom mattress suppliers in the UK:
- Bedfoam: Custom cut foam, £80-200 depending on size and density
- Foam for Comfort: Bespoke campervan mattresses, £150-400
- The Sleep Shop: Cut-to-order memory foam, £100-300
- Genuine Foam: UK-made, fast turnaround, £60-180
Mattress Thickness
| Thickness | Comfort | Best For |
|---|---|---|
| 50mm (2") | Basic | Foldable rock and roll beds |
| 75mm (3") | Moderate | Drop-down beds (weight saving) |
| 100mm (4") | Good | Standard fixed beds |
| 125mm (5") | Excellent | Premium comfort |
| 150mm (6") | Luxury | Full-time living |
Space consideration: A thicker mattress reduces the headroom above your bed. In a lowered bed with 45cm of headroom, a 15cm mattress leaves only 30cm.
Bedding Compatibility
UK standard duvet sizes for reference:
- Single: 135 x 200cm
- Double: 200 x 200cm
- King: 225 x 220cm
A small double mattress (120 x 190cm) takes single sheets. A 135cm double mattress takes standard double sheets. Non-standard sizes require fitted sheets from a specialist (or use flat sheets and tuck).
IKEA Mattress Hack
The IKEA Morgedal foam mattress (80cm x 190cm, single) is the most popular budget option for van builds. It is £50, comes in a vacuum-packed roll, and can be cut to size with an electric carving knife.
Tip: Buy two singles and glue them side by side with contact adhesive for a 160cm wide double.
Conclusion
Start with a standard UK mattress size if your layout allows. Single (90x190cm) for solo longitudinal beds, small double (120x190cm) or double (135x190cm) for transverse couples' beds. Only go custom when your van's dimensions force non-standard sizes.
Bottom line: The difference between a standard and custom mattress is £50-300. But a standard mattress can be replaced at any IKEA or bed shop. A custom one must be ordered with 2-3 weeks lead time.
