Top pick
RVMattress.comSignature Hybrid
- Hybrid
- 13.25 in thick
- Soft / Medium / Firm
Sleep Foundation: Best Mattress Overall Read review
$1,865RV King - 72x80 · list priceSee price
Forest River Sandpiper 399LOFT mattress size
Main bed72 × 80 inRV king
That's an RV king, 4 in narrower than a regular king (76 × 80 in). A regular king won't fit, so get an RV king in exactly 72 × 80 in.
About the RV king size →Forest River spec sheet, 2020.
Bunks44 × 74 in
Bunk. Forest River spec sheet, 2020.
Common RV bunk sizes →
Mattresses in 72 × 80 in
We may earn a commission when you buy through some of these links. It doesn't change which mattresses we list.
Best value
Mattress InsiderThe Sedona
- All-foam
- 5.5 in thick
- Firm
$40372" x 80" · 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 - 72x80 · list priceSee price
Best memory foam
Mattress InsiderElation Gel Foam
- Memory foam
- 6 in thick
- cushion firm
$65972" x 80" · list priceSee price
Best hybrid
RVMattress.comCopperFlex RV Hybrid
- Hybrid
- 10 in thick
- Medium-Firm
$1,065RV King 72x80 · 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 - 72x80 · list priceSee price
Reviewer pick
HelixHelix Midnight
- Hybrid
- 11.5 in thick
- Medium Feel
Sleep Foundation: Best Mattress for Side Sleepers Read review
$1,489RV King · list priceSee price
Reviewer pick
Mattress InsiderPark Meadow Encased Coil II
- Hybrid
- 8 in thick
- cushion-firm
Sleep Foundation: Best Mattress for Pressure Relief Read review
$84972" x 80" · list priceSee price
Bunk mattresses in 44 × 74 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 InsiderPark Meadow Encased Coil II
- Hybrid
- 8 in thick
- cushion-firm
Sleep Foundation: Best Mattress for Pressure Relief Read review
Made to 44 × 74 inGet a quote
Is this your 399LOFT?
Check the year and length against your RV before you order.
| Year | Model | Length | Sleeps |
|---|---|---|---|
| 2019 | Sandpiper Destination 399LOFT | – | 6 |
| 2020 | Sandpiper Destination 399LOFT | 40' 11" | – |
Other Sandpiper mattress sizes
Sources
Questions
What size mattress is in the Forest River Sandpiper 399LOFT?
The main bed is 72 × 80 in (Forest River spec sheet, 2020).
What size are the Forest River Sandpiper 399LOFT bunk mattresses?
44 × 74 in (Forest River spec sheet, 2020).