Tune M1 Mattress Dimensions
The M1 has two platform sizes depending on truck bed size. The mid-size platform (Tacoma, Ranger, Colorado) is 60" wide × 72" long. The full-size platform (Tundra, F-150, Ram 1500, Silverado) is 60" wide × 78" long. These are east-west platforms, your head and feet go across the width of the truck.
One thing to factor in: because you sleep across the 60" dimension, that's effectively your bed length. 60" is shorter than a standard mattress, so anyone 6 feet or taller will likely find the mid-size tight lengthwise. The full-size's extra 6" of platform length doesn't help (you're still sleeping across the 60" axis). The King Bed Extension changes this by adding ~20" of width over the cab, giving taller sleepers more room to stretch.
How the platform compares to standard mattress sizes:
| Mattress Size | Dimensions | Fits Mid-Size M1? | Fits Full-Size M1? |
|---|---|---|---|
| M1 Mid-Size Platform | 60" × 72" | — | — |
| M1 Full-Size Platform | 60" × 78" | — | — |
| Standard Twin | 38" × 75" | Too narrow (22" gap) | Too narrow (22" gap) |
| Twin XL | 38" × 80" | Too narrow (22" gap) | Too narrow (22" gap) |
| Short Queen | 60" × 75" | 3" trim needed (or 3" gap) | 3" gap at foot, usable |
| RV Short Queen | 60" × 74" | 2" trim needed (or 2" gap) | 4" gap at foot, usable |
| Custom cut foam | 60" × 72" or 60" × 78" | Perfect fit | Perfect fit |
The platform is a flat rectangle with no cutouts. The M1 ships without a mattress in the base price; Tune offers a Hest Dually Wide as a paid add-on (+$629), or you can source your own. Most owners go custom-cut foam from a supplier like Foam Factory for $80–$130.
Thickness & Headroom: The Key Tradeoff
Mattress thickness directly impacts how much headroom you have when sitting up in bed. With a 4" mattress installed (the most common owner choice), there's 30.5" of clearance between the top of the mattress and the ceiling of the pop-top. How thickness affects that headroom:
| Mattress Thickness | Sitting Headroom | Assessment |
|---|---|---|
| 3" | ~31.5" | Most headroom, but less comfortable sleep for most people |
| 4" (standard) | 30.5" | Community sweet spot: comfortable sleep + generous headroom |
| 5" | ~29.5" | Still workable for most: noticeably better sleep quality |
| 6" | ~28.5" | Starts to feel low for taller campers sitting upright |
| 8"+ | ~26.5" or less | Most people find this uncomfortably cramped for sitting |
Mattress Types: What Works in the M1
Memory Foam
Most popular choice for M1 owners. Conforms well, compresses for loading, and is available in custom sizes. Sleeps warmer than latex, which can be a pro or con depending on your typical climate.
Latex Foam
More breathable than memory foam, bounces back quickly, and is naturally more durable. Heavier than memory foam of the same size. High-quality latex is noticeably more comfortable but significantly more expensive.
Hybrid (Spring + Foam)
Good comfort but hard to find in custom sizes. Springs add weight. Generally not the first choice for a truck camper application unless you're coming from a specific preference.
Standard RV / Camping Pads
Lightweight option but typically compromises on comfort for extended use. Fine for occasional overnights; most full-time or regular M1 users upgrade quickly.
Top Picks: What M1 Owners Are Sleeping On
The Custom Cut Foam Option
This is the most popular approach in the M1 community, and for good reason. You order foam cut to your exact platform dimensions. No compromise on fit, no struggling with a mattress that's an inch too wide.
Ordering custom foam is simpler than it sounds:
- Go to Foam Factory (foambymail.com) or a similar custom foam supplier
- Select your foam type: HD36-R (2 lb/ft³ high-resilience) is the community-recommended density for sleeping comfort
- Enter your dimensions: 60" × 72" (mid-size) or 60" × 78" (full-size), and your preferred thickness (4" is standard)
- Add a mattress cover or use a standard fitted sheet, the foam ships bare; a zippered cover keeps it clean
For a cover: a standard Short Queen fitted sheet (60" × 75") works on mid-size platforms with a little slack. For a cleaner fit, order a custom mattress cover from the same supplier, or use a fabric zippered protector.
Weight Considerations
Every mattress adds payload weight. A rough comparison at M1 platform dimensions (60" × 72" mid-size):
| Mattress type | Thickness | Approx. weight |
|---|---|---|
| Memory foam (2 lb/ft³) | 4" | ~15–18 lbs |
| Memory foam (2 lb/ft³) | 5" | ~19–23 lbs |
| Memory foam (3 lb/ft³, premium density) | 4" | ~22–27 lbs |
| Latex foam | 4" | ~28–35 lbs |
| Hybrid (spring + foam) | 8–10" | ~45–65 lbs |
A standard 4" foam upgrade adds roughly 15–18 lbs, a manageable payload cost. Jumping to a premium 6" latex adds 35+ lbs. Use the payload calculator to factor your mattress choice into your full build weight.