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Images: Casper. Shown size and configuration may vary.

Casper

The One

Name: Casper The One
Brand: Casper

Best for: Classic all-foam, firmer side

An 11″ three-layer foam bed that Casper rates medium firm, in every size including Split King.

Good to know: Returns can't start until you've slept on it 30 nights.

Type: Foam
Height: 11″
Sizes: 6 ready-made
Weight (queen): 76 lb

Firmness, according to reviewersMedium firm

Pick it if

You sleep on your back
You sleep on your stomach
You share the bed

Skip it if

You sleep on your side
You’re a heavier person

From independent reviewers’ findings, credited below.

Your size

38 × 75 in · 11″ tall

Where to get it

casper.comQueen $899 (sale price) · checked Oct 16 See price
Split kingSplit King See the list

Returns: 100 nights from delivery; returns can start after a 30-night adjustment period Details

We may earn a commission if you buy. Check the price for your exact size and height on the seller’s site.

The short version

Worth a look if

Classic all-foam, firmer side

Good

An 11″ three-layer foam bed that Casper rates medium firm, in every size including Split King.
Trial: 100 nights from delivery; returns can start after a 30-night adjustment period
A 6-12 month side sleeper and a 2-year stomach sleeper rated pressure relief 5 out of 5 and sleep quality 4-5.
Height: 11″

Think about

Returns can't start until you've slept on it 30 nights.
Three 5-year side sleepers and a recent first-year owner rated back support 2 out of 5, with sleep quality also around 2.
Standard sizes only: no RV, odd or custom sizes listed

Based on the maker’s published specs and terms, and the owner reviews linked below. We haven’t slept on it. Something wrong? Tell us.

What owners say

From owners of a related model A small set of real reviews, each linked to its source. Not a star rating.

Small sample · 10 owner reports

GoodBed owners of the Casper One were mixed: some side and stomach sleepers rated it well, but several 5-year side sleepers rated back support and pressure relief low.

What people liked

A 6-12 month side sleeper and a 2-year stomach sleeper rated pressure relief 5 out of 5 and sleep quality 4-5. Source ↗

What to weigh up

Three 5-year side sleepers and a recent first-year owner rated back support 2 out of 5, with sleep quality also around 2. Source ↗

What independent reviewers found

NapLab (May 2026): The reviewer found a medium-firm, float-on-top feel with little hug and a thin comfort layer, so side sleepers and heavier people may feel pressure; lighter sleepers did fine in any position. Sitting on the edge felt solid but lying there was only fair, motion died out quickly, it ran about average for heat, and a strong smell took about 12 days to fade. Their unit measured 10″ against Casper's listed 11″. Affiliate commissions disclosed; the reviewer also discloses a settled 2016 lawsuit with Casper. Read it ↗
Sleepopolis (Oct 2024): Testers found it a bit firmer than medium-firm with an on-top feel: good alignment for light and average back sleepers, less shoulder relief for side sleepers, and too much sink for heavier sleepers. Edges felt stable, motion barely carried in their tests, and it didn't feel cool to the touch though it didn't overheat testers. Article updated 2024. Sleepopolis earns affiliate commissions. Read it ↗
Tom's Guide (Mar 2025): Three weeks of testing. Felt medium-firm, slightly firmer than labelled; best for back and stomach sleepers, too firm for light side sleepers. Outstanding motion isolation, average temperature control with some heat retention, edges dip under weight. Queen tested in winter. Prices quoted are from March 2025. Page carries retailer deal widgets (affiliate). Read it ↗

Their testing, in our words. We haven’t tested these mattresses ourselves, and we don’t repeat their scores.

Sources & sample limits

10 ratings-only GoodBed reviews naming 'Casper One', Sep 2024-Sep 2026 Sample: 10 owner reports.

Many owners report 5-8 years of use, longer than the current The One has been sold, so they likely own an earlier Casper all-foam bed listed under this name. Ratings only. RedditRecs comments for The One mostly say just 'Casper' without the model, so they were not used.

Research checked October 14, 2026. These are sourced observations, not our own product tests or a star rating.

Every size it comes in

Twin38 × 75 in11″Twin XL38 × 80 in11″Full · 53-inch53 × 75 in11″Queen60 × 80 in11″King76 × 80 in11″California king72 × 84 in11″

Taken from the maker’s size options, in the inches it publishes. Tap a size to compare every mattress made in it.

Price for every size

From the maker’s site on Oct 26, 2026. Prices change often, so check before you buy.

Size	Inches	Price
Twin	38 × 75	$874	See it
Twin XL	38 × 80	$974	See it
Full	53 × 75	$1,074	See it
Queen	60 × 80	$1,149	See it
Cal King	72 × 84	$1,649	See it
King	76 × 80	From $1,649	See it

Video reviews

The One · Review

Casper One Mattress Review - Casper's New Budget-Friendly Mattress

NapLab · YouTube ↗

The One · Review

Casper Mattress Review - Reviewing The Casper One Mattress!

Mattress Clarity · YouTube ↗

How it compares

Beside the most similar mattresses from other brands.

	The OneCasper	Classic Memory FoamDreamCloud	Premier Memory FoamDreamCloud	Original MattressLeesa
Type	Foam	Memory foam	Memory foam	Memory foam
Queen price	$899	$799	$1,199	$1,059
Height	11″	12″	13″	10″
Trial	100 nights	365 nights	365 nights	365 nights
Odd sizes	None	None	None	None
Expert reviews	3	3	4	3

What’s inside

1Cozy Cover
2Breathable polyurethane foam
3Memory foam
4Polyurethane foam base

Feel: Medium Firm
Height: 11″
Custom sizes: Not offered for this model

Returns and ordering

Trial and returns

100 nights from delivery; returns can start after a 30-night adjustment period

Before you order

Measure inside the frame, not the old mattress
Check clearance above for the height you pick
Make sure your base supports it
Buy sheets in the same exact size

Questions

What is it made of?

All-foam: breathable polyurethane foam over memory foam over a durable polyurethane foam base, with Casper's Cozy Cover and continuous support.

How firm is it?

Medium Firm That’s the maker’s description; we haven’t measured it.

Which sizes and heights can I get?

6 sizes, 11″. See every size. Confirm your exact size and height with the seller.

Are the reviews about this exact mattress?

From owners of a related model. Many owners report 5-8 years of use, longer than the current The One has been sold, so they likely own an earlier Casper all-foam bed listed under this name. Ratings only. RedditRecs comments for The One mostly say just 'Casper' without the model, so they were not used.

Where did this information come from?

Checked 2026-10-16. Specs and terms can change.