rigsize

Keystone Alpine 3700FL mattress size

Years 2020–2026Sold as AlpineLength 41 ft 5 inSleeps 6
70 in 80 in
To scale. Dashed: a regular queen.
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 2024 brochure, 2024.

Mattresses in 70 × 80 in

We may earn a commission when you buy through some of these links. It doesn't change which mattresses we list.

Top pick
RVMattress.com Signature Hybrid

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
Best value
RVMattress.com CopperFlex Essential

RVMattress.comCopperFlex Essential

  • All-foam
  • 6 in thick
  • five comfort options
$799RV King - 70x80 · list priceSee price
Reviewers' favorite
RVMattress.com Aurora Luxe Cooling

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.com CopperFlex RV Hybrid

RVMattress.comCopperFlex RV Hybrid

  • Hybrid
  • 10 in thick
  • Medium-Firm
$1,065RV King - 70x80 · list priceSee price
Best all-foam
RVMattress.com Plank Firm

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 Insider Park Meadow Encased Coil II

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
Bedroom in a Alpine

The Alpine bedroom. Measure the platform, not the old mattress, before you buy.

Bed sizes by year

YearMain bedBunksOther bedsSource
202170 × 80 in King––Keystone 2021 brochure
202270 × 80 in––Keystone 2022 brochure
202470 × 80 in King––Keystone 2024 brochure

Years not listed weren't published.

Is this your 3700FL?

Check the year and length against your RV before you order.

YearModelLengthSleeps
2020Alpine 3700FL41 ft 5 in6
2021Alpine 3700FL41 ft 6 in6
2022Alpine 3700FL41 ft 6 in6
2023Alpine 3700FL41 ft 5 in6
2024Alpine 3700FL41 ft 5 in6
2025Alpine 3700FL41 ft 5 in6
2026Alpine 3700FL41 ft 5 in6

Other Alpine mattress sizes

Sources

  1. Keystone (keystonerv.com): https://www.keystonerv.com/product/alpine/luxury-fifth-wheels/floorplans/3700FL

Questions

What size mattress is in the Keystone Alpine 3700FL?

The main bed is 70 × 80 in (Keystone 2024 brochure, 2024).