rigsize

Forest River Flagstaff 21HSB mattress size

Years 2026Sold as Flagstaff HardsideLength 18' 5"
60 in 80 in
To scale. Dashed: a regular queen.
Main bed60 × 80 inQueen

That's the same size as a regular queen, so any standard queen mattress fits.

About the RV queen size →

2026 Forest River Flagstaff Tent Campers brochure, 2026.

Bunks (1)32 × 80 in Bunk. 2026 Forest River Flagstaff Tent Campers brochure, 2026. Common RV bunk sizes →

Mattresses in 60 × 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

$1,465Queen · list priceSee price
Best value
Mattress Insider The Sedona

Mattress InsiderThe Sedona

  • All-foam
  • 5.5 in thick
  • Firm
$36160" x 80" · 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

$1,999Queen · list priceSee price
Best memory foam
Mattress Insider Elation Gel Foam

Mattress InsiderElation Gel Foam

  • Memory foam
  • 6 in thick
  • cushion firm
$45960" x 80" · list priceSee price
Best hybrid
RVMattress.com CopperFlex RV Hybrid

RVMattress.comCopperFlex RV Hybrid

  • Hybrid
  • 10 in thick
  • Medium-Firm
$799Queen · 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

$1,332Queen · list priceSee price
Reviewer pick

HelixHelix Midnight

  • Hybrid
  • 11.5 in thick
  • Medium Feel

Sleep Foundation: Best Mattress for Side Sleepers Read review

$1,183Queen · list priceSee price
Reviewer pick
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

$66960" x 80" · list priceSee price

Bunk mattresses in 32 × 80 in

Some bunks have a rounded corner, so trace yours before a custom cut. A thicker bunk mattress takes headroom from the bunk above.

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 32 × 80 inGet a quote
Bedroom in a Flagstaff

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

The 21HSB floorplan

Forest River Flagstaff 21HSB floorplan, 2026

Forest River's 2026 21HSB floorplan.

Is this your 21HSB?

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

YearModelLengthSleeps
2026Flagstaff Hardside T21HSB18' 5"–

Other Flagstaff mattress sizes

10LE10RB12FD12RG12ST21HSAll Flagstaff floorplans

Sources

  1. recreationalvehicles.info: https://recreationalvehicles.info/2026-forest-river-flagstaff-tent-campers/2026-forest-river-flagstaff-tent-campers-brochure-page-002.jpg
  2. recreationalvehicles.info: https://recreationalvehicles.info/2026-forest-river-flagstaff-tent-campers/2026-forest-river-flagstaff-tent-campers-brochure-page-007.jpg

Questions

What size mattress is in the Forest River Flagstaff 21HSB?

The main bed is 60 × 80 in (2026 Forest River Flagstaff Tent Campers brochure, 2026).

What size are the Forest River Flagstaff 21HSB bunk mattresses?

32 × 80 in (2026 Forest River Flagstaff Tent Campers brochure, 2026).