BedInABox Tranquillium Mattress Review

Based on Q&A session with our Chief Sleep Science Editor,

Last updated | January 31, 2024 provides objective and unbiased recommendations to help you find the best mattress for you. When you use our links to shop for products, we may earn a commission at no cost to you and in no way affects our editorial independence.

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BedInABox Tranquillium Mattress


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BedInABox Tranquillium Mattress

By Brand: BedInABox
4 out of 5.0
$1729 $864

Product Description

The Tranquillium mattress is an all-foam offering from the stable of BedInABox. This bed offers you a perfect blend of CoolRest memory foam and Sure Align support foam for excellent comfort. At 12-inches in height, the Tranquillium mattress is categorized as a firm bed. Thus, you shall get ample support and greater spine alignment while sleeping.

The comfort layer of the Tranquillium is made up of CoolRest gel memory foam. A Plauralux transition layer follows this layer. The support base of the bed has Sure Align support foam. The cover of the mattress is made up of a smooth knit fabric.

The Tranquillium mattress is available in Twin, Twin XL, Full, Queen, King, and Cal King sizes.

Other models from the stable of BedInABox include The Essential, Original, Azul, Dual Hybrid, and Eco-Lux mattresses.

This section will review the BedInABox Tranquillium Mattress in detail.

  • Material: CoolRest Memory Foam, Plauralux Transition Foam, Sure Align Support Foam
  • Sizes: Twin, Twin XL, Full, Queen, King, and Cal King sizes.
  • Pricing: Depends on size & variety
  • Shipping & Delivery: Free Shipping
  • Trial & Return: 120-night Trial and Free Returns
  • Warranty: 20-year Warranty

Pros & Cons


  1. The mattress shows decent cooling performance
  2. Exhibits low motion transfer, ensuring minimal disturbances during sleep.
  3. Provides pressure relief by contouring and supporting your body.


  1. Low bounce causing delayed movements
  2. Sitting edge support although adequate for lying on the edge is not highly decent
  3. Response time is within acceptable range.


The Tranquillium Mattress is a reasonably firm bed. Its dense layers keep your body well supported and promote excellent spine alignment.

This mattress offers you more excellent responsiveness. The 3-inch memory foam layer provides some comfort. Beneath the comfort layer lays a 2-inch Plauralux foam transition layer for gradual support. The support core of the Tranquillium is made up of a 7-inch Sure Align foam that offers more significant support and spine alignment.

Material & Construction

The BedInABox Tranquillium is an all-foam mattress featuring CoolRest gel memory foam, Plauralux transition foam, and Sure Align support foam. It stands 12-inches tall and rates as a firm bed.

The cover of the Tranquillium mattress is made up of a smooth knit fabric.

The comfort layer of this mattress uses 3-inches of 3 lb CoolRest memory foam. This layer is gel-infused and offers excellent pressure relief and cooling.

Beneath the comfort layer comes the 2-inch thick transition layer. This layer is made up of Plauralux foam. It gradually transitions from the comfort layer to the firmer support base.

The support core of the Tranquillium is made up of 7-inches of 2 lb Sure Align foam. This layer is designed to keep your body well supported and promote better spine alignment.


  • Layer 1: This is the comfort layer of the mattress, made up of 3-inches of 3 lb CoolRest gel memory foam.
  • Layer 2: This is the 2-inch transition layer featuring Plauralux foam for a gradual transition to the base of the mattress.
  • Layer 3: This layer forms the support core of the Tranquillium mattress. It is made up of 7-inches thick, 2 lb Sure Align foam.


BedInABox Tranquillium Mattress
Materials & Construction (1=Least, 5=Best) (4.25/5)
Repositioning (1=Least, 5=Best) (4.00/5)
Comfort (1=Least, 5=Best) (4.00/5)
Cooling (1=Least, 5=Best) (3.75/5)
Motion Isolation (1=Least, 5=Best) (4.00/5)
Edge Support (1=Least, 5=Best) (4.00/5)
Overall Rating 4/5
Rating Scale: 1 = Average, 2 = Good, 3 = Very Good, 4 = Excellent, 5 = Winner



Repositioning refers to how easily you can change your position on the bed.

Being firm, the Tranquillium mattress offers greater ease of movement and repositioning. The mattress makes a close conforming to your body. Thus, you won’t feel stuck while moving on the bed.

Comfort, Back Support, Pressure Relief


Comfort, pressure relief, and support are vital factors to consider while choosing a mattress.

The Tranquillium offers superior support and spine alignment as a firm all-foam mattress. This bed does not conform too closely to your body. Thus you will receive moderate pressure relief from the Tranquillium.

The comfort layer offers some pressure relief in the key regions. However, you won’t sink into the bed. The transition layer of the bed provides some support and a gradual transition to the base layer. The high-density base layer gives the mattress its support. The Sure Align foam promotes great spine alignment and keeps your body well supported.

The loose conforming nature does not make you feel trapped in the Tranquillium and promotes cooler sleeping.

Consider your sleeping position to determine how well the Tranquillium Mattress shall suit you.

  • Side Sleepers: Being a firm mattress, the Tranquillium shall best suit heavyweight side sleepers weighing over 230 lbs. Such sleepers might experience slight contouring near their shoulders and hips. Lightweight sleepers might prefer a softer bed for more comfort.
  • Back Sleepers: Average weight back sleepers weighing over 130 lbs should sleep well on the Tranquillium. The firm nature of this mattress promotes excellent spinal alignment, while the comfort layers allow for the hips of the back sleepers to sink in slightly.
  • Stomach Sleepers: The Tranquillium is excellent for stomach sleepers across all weight categories. This firm mattress offers excellent support and prevents too much sinkage. Thus, you shall not worry about your spine bending uncomfortably while sleeping on this bed.
  • Heavy Sleepers: The Tranquillium is a good choice for heavy sleepers. Such sleepers shall find the perfect blend of support and comfort required while sleeping. The firm nature of the bed should prevent them from sinking too deep into the bed.

Cooling & Temperature Control


Generally, all-foam mattresses tend to trap heat. But the gel infusion in the Tranquillium’s memory foam layer helps wick away body heat. The firm nature of the bed makes a loose conforming to the sleeper’s body, thereby allowing for more airflow. This enables you to enjoy a cooler sleep.

Motion Isolation and Sharing a Bed


Motion isolation is the ability of a mattress to prevent sleepers from feeling when their partner moves.

Being an all-foam mattress, the Tranquillium performs quite well in absorbing motion transfer. The dense foam layers prevent motion from traveling to other bedsides. Thus, you can rest assured of getting a peaceful night’s sleep without feeling it when your partner moves.

Edge Support


Edge support refers to how sturdy a mattress is near the sides. Firm edge support implies greater usable area on the bed.

Most all-foam mattresses lack proper edge support. However, the firm Tranquillium mattress performs well in this respect. The dense foam layers prevent you from sinking too deep into the bed. Thus, you won’t have to worry about rolling off while sleeping or lying on the edges.

Recommendation based on sleeping style

Sleeping is one of the most rejuvenating tasks. Therefore, you must get the most comfortable sleep for a refreshing day.

The Tranquillium mattress offers you the best support and spine alignment. This bed is pretty firm. You won’t get that sinking-in sensation while sleeping on the Tranquillium. The CoolRest comfort layer offers some pressure relief, while the transition layer and the support base layer add bounce and support.

Its firm nature and the gel infusion in the memory foam layer enable you to sleep cool on the Tranquillium mattress. The loose conforming nature of the bed also helps prevent heat-trapping, thereby allowing you to sleep cooler.

  • Side Sleepers: Side sleepers need a softer bed for more outstanding cushioning near the key pressure-building areas. Being firm in feel, the Tranquillium mattress shall best suit heavyweight side sleepers weighing over 230 lbs. Such sleepers should experience some sinkage and pressure relief. Lightweight sleepers might not find the Tranquillium comforting due to its firmness and may prefer a softer bed.
  • Back Sleepers: Back sleepers need a more supportive mattress to keep their spines adequately aligned and allow the hips to sink in slightly. Average weight back sleepers weighing over 130 lbs should sleep comfortably on the Tranquillium. Such sleepers shall get the perfect blend of support and sinkage. Heavier sleepers weighing over 230 lbs. should also sleep well on this mattress. However, lightweight sleepers under 130 lbs might find the Tranquillium slightly firmer.
  • Stomach Sleepers: Stomach sleepers require a more supportive mattress for proper lumbar support and spine alignment. These sleepers across any weight category should sleep quite comfortably on the Tranquillium bed. Its firm structure shall offer the stomach sleepers the necessary support and prevent their spines from bending too much.
  • Combination Sleepers- Those who alternate between various positions: Combination sleepers keep changing their position throughout the night. Therefore, they must choose a bed that will provide them with the perfect blend of support and comfort. The Tranquillium mattress shall suit you the best if you’re an average to heavyweight combination sleeper. In case you’re a lightweight person, you may prefer something softer.


Size Price Sale Price Discount
Twin $1149 $574 50%
Twin XL $1259 $629 50%
Full $1499 $749 50%
Queen $1729 $864 50%
Cal King $1949 $974 50%
King $1949 $974 50%
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