Top pick
RVMattress.comSignature Hybrid
- Hybrid
- 13.25 in thick
- Soft / Medium / Firm
Sleep Foundation: Best Mattress Overall Read review
$1,865RV King - 70x80 · list priceSee price
Keystone Sprinter 3840LRK mattress size
Main bed70 × 80 inRV king
That's an RV king, 6 in narrower than a regular king (76 × 80 in). A regular king won't fit, so get an RV king in exactly 70 × 80 in.
About the RV king size →Keystone spec page, 2027.
Mattresses in 70 × 80 in
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Best value
RVMattress.comCopperFlex Essential
- All-foam
- 6 in thick
- five comfort options
$799RV King - 70x80 · list priceSee price
Reviewers' favorite
RVMattress.comAurora Luxe Cooling
- Hybrid
- 13.25 in thick
- Soft / Medium / Firm
Sleep Foundation: Best Mattress for Temperature Regulation Read review
$2,465RV King - 70x80 · list priceSee price
Best hybrid
RVMattress.comCopperFlex RV Hybrid
- Hybrid
- 10 in thick
- Medium-Firm
$1,065RV King - 70x80 · list priceSee price
Best all-foam
RVMattress.comPlank Firm
- All-foam
- 10 in thick
- Firm / Extra Firm
Mattress Clarity: Best RV Mattress for Heavy People Read review
$1,532RV King - 70x80 · list priceSee price
Custom size
Mattress InsiderPark Meadow Encased Coil II
- Hybrid
- 8 in thick
- cushion-firm
Sleep Foundation: Best Mattress for Pressure Relief Read review
Made to 70 × 80 inGet a quote
The Sprinter bedroom. Measure the platform, not the old mattress, before you buy.
Bed sizes by year
| Year | Main bed | Bunks | Other beds | Source |
|---|---|---|---|---|
| 2026 | 70 × 80 in King | – | – | Keystone 2026 brochure |
| 2027 | 70 × 80 in King | – | – | Keystone spec page |
Years not listed weren't published.
The 3840LRK floorplan
Keystone's 2027 3840LRK floorplan.
Is this your 3840LRK?
Check the year and length against your RV before you order.
| Year | Model | Length | Sleeps |
|---|---|---|---|
| 2025 | Sprinter 3840LRK | 42 ft 4 in | 4 |
| 2026 | Sprinter 3840LRK | 42 ft 10 in | 4 |
| 2027 | Sprinter 3840LRK | 42 ft 10 in | 4 |
Other Sprinter mattress sizes
Sources
- Keystone (keystonerv.com): https://www.keystonerv.com/product/sprinter/premium-fifth-wheels/floorplans/3840LRK
Questions
What size mattress is in the Keystone Sprinter 3840LRK?
The main bed is 70 × 80 in (Keystone spec page, 2027).