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Deal.ai › Casper › Mattresses
Casper
Casper Slate Firm Mattress 10.5"

Casper Slate Firm Mattress 10.5"

Best price now

$395.00at Mancini's SleepworldObserved at 5:53 AM

34% under what the other stores charge

Compared across 4 stores. Prices are checked against each store and labelled with when.

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Price facts

  • Lowest price today: $395.00 at Mancini's Sleepworld (checked Nov 9, 2026).
  • Checked at 4 stores.

Our take on the Casper Slate Firm Mattress 10.5"

The Casper Slate is a 10.5-inch all-foam mattress with a medium-firm feel that balances support and pressure relief. It pairs a memory foam layer with a breathable soft-knit cover to help manage heat, and the foam is CertiPUR-US certified. It suits back and stomach sleepers and couples who want motion isolation, though side sleepers who like a soft bed and anyone who needs strong edge support should look at a hybrid instead.

Best forBack and stomach sleepersCouples needing motion isolationShoppers wanting a mattress-in-a-boxHot sleepers who prefer foam
Pros
  • CertiPUR-US certified foam
  • Effective pressure relief for joints
  • Compatible with adjustable bases
  • Breathable cooling foam layers
  • Minimal motion transfer
Cons
  • Lacks the edge support of hybrid models
  • May feel too stiff for lightweight side sleepers
  • Initial off-gassing odor after unboxing

Casper Slate Firm Mattress 10.5" prices at every store

  • Mancini's SleepworldNew

    In stock

    $395.00Observed at 5:53 AM
    Visit Mancini's Sleepworld
  • Christian's Mattress XpressNew

    In stock

    $595.00Observed at 5:53 AM
    Visit Christian's Mattress Xpress
  • JCPenneyNew

    In stock

    $1,195.00Free shippingObserved at 5:53 AM
    Visit JCPenney
  • PC Richard & SonNew

    Out of stock

    $499.97Observed at 5:53 AM
    Visit PC Richard & Son

Store links may earn us a commission. Some prices via Klarna.

Casper Slate Firm Mattress 10.5" price history

$395.00$395.00
Nov 7Nov 9

Lowest price we've seen: $395.00 on Nov 7 at Mancini's Sleepworld. Tracked across 4 stores since Nov 7.

What reviewers say

Owners generally appreciate the Slate for its firm support that doesn't feel like a hard board, though some note it takes a few days to fully expand. It is frequently cited for helping with lower back pain.

What people mention
  • FirmnessPraisedUsers find the medium-firm rating accurate, providing a stable surface that prevents sinking.
  • TemperatureMixedWhile the cooling layer helps, some users find it still retains more heat than an innerspring mattress.
  • Edge SupportCriticisedReviewers mention the perimeter can feel soft when sitting on the very edge of the bed.
  • ExpansionMixedOwners say the mattress needs a few days to reach full height after unboxing.
  • Off-gassingCriticisedA noticeable scent lingers for the first day or two after the box is opened.

Specifications

Firmness Level
Medium-firm
Mattress Type
Memory Foam
Type
Mattress
Length
80 in
Width
38 in
Certifications
Certipur-Us Certified
Core Material
Foam
Cover Material

Questions and answers

Is the Casper Slate good for back pain?
Yes, its medium-firm foam construction is designed to provide the spinal alignment and pressure relief often recommended for back sleepers.
Does it require a specific foundation?
It can be used on a flat platform, a bunkie board, or an adjustable base, but it should not be used with a traditional box spring.
How long does it take to expand?
Most users find it reaches full height within 24 to 72 hours after being removed from the box.
Is the cover machine washable?
No, the soft-knit cover should be spot cleaned only to avoid damaging the fabric or the foam underneath.
How does the Slate differ from the Casper Original?
The Slate is the firmer all-foam option with a tighter top and a dedicated memory foam layer, while the Original uses a softer zoned foam design aimed at a broader range of sleepers.
What sizes does the Slate come in?
It is sold in the standard mattress sizes from twin through king, including the king listed here at 80 by 38 inches per side.
Where is the Casper Slate Firm Mattress 10.5" cheapest?
At Mancini's Sleepworld, for $395.00, 34% under what the other stores charge, as of our latest check.
Where can I buy the Casper Slate Firm Mattress 10.5"?
4 stores we checked sell it, including JCPenney, Mancini's Sleepworld, PC Richard & Son, Christian's Mattress Xpress.

Stores we've priced the Casper Slate Firm Mattress 10.5" at

  • JCPenney deals and prices
  • Mancini's Sleepworld deals and prices
  • PC Richard deals and prices

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Soft-knit cover
Material
Foam
Foundation Type
Adjustable Base
Foundation Included
No
Fill Material
Foam, Memory Foam
Fill Type
Memory Foam
Fill Style
Medium-firm
Care Instructions
Spot Clean
Construction Highlights
Tight Top, Mattress In A Box
Handcrafted
No
Specialty Style
Tight Top
Solution For
Prevent overheating, Pressure-relieving
Bed Size
KingSource
Comfort Level
FirmSource
Filling
FoamSource