Top Foundations for King Memory Foam Mattresses: Our Expert Picks - Inn Mattress

As a mattress expert and editor at Innmattress, I know that choosing the right foundation is just as important as selecting the perfect mattress. A good foundation can enhance your sleep quality by providing optimal support, stability, and durability to your mattress. However, not all foundations are created equal – especially when it comes to memory foam mattresses.

In this article, I’ll share our top picks for the best foundations for king memory foam mattresses. We’ve scoured the market to find products that meet our criteria for excellent performance, quality construction, and user satisfaction. Whether you’re looking for an adjustable base or a classic box spring foundation, we’ve got you covered.

What to Look For in a Foundation?

Before we dive into our recommendations, let’s take a closer look at what features you should consider when shopping for a foundation:

  1. Sturdy Construction: The foundation must be firm enough to provide stable support without sagging or collapsing over time.
  2. Compatibility with Your Mattress: Your foundation’s size and load capacity must match your mattress’s dimensions and weight requirements.
  3. Durability: You want something that will last long-term without losing its shape or functionality
  4. Noise Reduction: Squeaky beds could disrupt sleep; therefore noise reduction is important if you have sensitive ears or if your partner frequently moves throughout the night.
  5. Adjustability Features (Optional): If you prefer reading in bed or suffer from back pain- an adjustable base can help aid in preventing these issues.

Top Foundations for King Memory Foam Mattresses

Now that we know what factors make up an effective foundation let’s explore some of our favorite recommendations:

1) Amerisleep Adjustable Bed+

Amerisleep Adjustable Bed+
Amerisleep Adjustable Bed+

Type: Adjustable Bed
Price Range: $1,299 – $2,699
Available Sizes & Dimensions:

  • Twin XL: 37” W x 79” L, Product Weight 119 lbs.
  • Full: 53” W x 74” L, Product Weight 145 lbs.
  • Queen: 59″ W x 79″ L, Product Weight 148 lbs.
  • King: 75” W x 79″ L, Product Weight 238 lbs.
  • California King: 71” W x 83″ L, Product Weight 238 lbs.
  • Split King: 75” W x 79″ L, Product Weight 238 lbs.

Materials & Certifications:

  • Free Shipping
  • 10-Year Warranty


  • Head-foot adjustability offers tailored comfort for various sleep positions.
  • Zero Gravity and Anti-Snore presets enhance sleep quality.
  • Massage modes and a gentle night light provide added relaxation.
  • Wall Glide feature keeps you close to your nightstand.
  • Free next-day shipping and a 10-year warranty add value.


  • Installation cost of $279.30 may be a downside for some.
  • Higher price point may not be suitable for all budgets.
  • Limited mattress bundle options for King and California King sizes.

Bottom Line – Why It Makes the Cut

The Amerisleep Adjustable Bed+ is a game-changer in the realm of sleep technology. With its head-foot adjustability and specialized presets like Zero Gravity and Anti-Snore, this bed base is designed to transform your sleep experience. While the installation cost and higher price point may deter some, the plethora of features and robust 10-year warranty make it a worthwhile investment for those seeking elevated comfort and functionality.

How It Performed

The Amerisleep Adjustable Bed+ has received an average rating of 4.8 stars from over 550 reviews, making it a highly rated product in the adjustable bed market. The bed base performed exceptionally well in terms of comfort, adjustability, and added features like massage modes and a night light. Users particularly appreciated the Wall Glide feature, which allows the bed to adjust while maintaining proximity to the nightstand.

The bed base is available in multiple sizes, each with its own set of dimensions and weight, offering options for various room sizes and user needs. The 10-year warranty and free next-day shipping are additional perks that contribute to a satisfying user experience.

What It’s Made Of

The Amerisleep Adjustable Bed+ is crafted with durability and user comfort in mind. While the material specifics are not detailed, the 10-year warranty suggests a high level of confidence in the product’s longevity and performance.

If you’re in the market for an adjustable bed that offers both comfort and cutting-edge features, the Amerisleep Adjustable Bed+ is a top contender. Its range of sizes and weight options make it versatile, while the added features and robust warranty make it a solid long-term investment for quality sleep.

2) Zinus Smartbase Elite Metal Platform Bed Frame

Zinus Smartbase Elite Metal Platform Bed Frame
Zinus Smartbase Elite Metal Platform Bed Frame


  • Heavy-Duty Construction: Made from thick and durable solid steel, this frame can support up to 4400 lbs.
  • Tool-Free Assembly: No need for a toolbox; the frame is easy to assemble.
  • Under-Bed Storage: Offers 13 inches of clearance for under-bed storage.
  • 5-Year Warranty: Comes with a long-term warranty for peace of mind.


  • Height Variability: Limited to 14″, 16″, and 18″ options, which may not suit all preferences.
  • Weight: The frame itself can be quite heavy, especially in larger sizes.

Bottom Line – Why It Makes the Cut

The Zinus Smartbase Elite Metal Platform Bed Frame is a heavy-duty, high-performance foundation that promises to keep your mattress in optimal condition for years to come. With its robust steel construction, tool-free assembly, and ample under-bed storage, it’s a practical choice for anyone looking to upgrade their bedroom setup.

Product Details

The Zinus Smartbase Elite is more than just a bed frame; it’s a heavy-duty mattress foundation designed to provide unparalleled support. Available in sizes ranging from Twin to Cal King, the frame is engineered with thick, durable steel that can support up to a whopping 4400 lbs.

Core Composition & Dimensions
  • Core Composition: Steel Frames and wires
  • Dimensions for 18″ Queen: 80″ X 60″ X 18″, 36.2 lb
  • Underbed Clearance Space: 17″ for 18″ height option
Additional Features
  • 30-Day Return Policy: If you’re not satisfied, you can return it within 30 days.
  • Free Shipping: The product ships for free.
  • Smartly Shipped: Comes in one compact, easy-to-maneuver box.

How It Performed

The Zinus Smartbase Elite stands out for its exceptional durability and ease of assembly. The heavy-duty steel frame ensures that your mattress is well-supported, eliminating any concerns about sagging over time. The 13-inch under-bed clearance is a boon for those looking to maximize storage space.

The tool-free assembly is a game-changer, making the setup process a breeze even for those who aren’t particularly handy. The frame is also smartly shipped in a single, compact box, making it easy to maneuver through tight spaces during the unboxing process.

What It’s Made Of

The core composition of the Zinus Smartbase Elite is made entirely of steel frames and wires, ensuring maximum durability and support. The frame is designed to have multiple points of contact with the floor, further enhancing its stability.

The Zinus Smartbase Elite Metal Platform Bed Frame is a top-tier choice for anyone in search of a sturdy, reliable, and easy-to-assemble bed frame. With its heavy-duty construction and user-friendly design, it offers a level of quality and convenience that is hard to beat.

3) Saatva Classic Mattress Foundation

Saatva Classic Mattress Foundation
Saatva Classic Mattress Foundation

Price Range:
$215 – $430 depending on size

Handcrafted from North American spruce, CertiPUR-US® foams, and an organic cotton cover

Foundation Height Options:
Multiple (Details not provided)

Additional Features:

  • More durable than a traditional box spring
  • Creates a seamless look with your Saatva mattress
  • Optional Universal Frame for an additional $129

As low as $20/month at 0% APR with Affirm

Special Offers:
15% off orders $1000+ (Limited Time)


  • Optimal Support: The foundation is designed to offer a stable, comfortable sleep surface, enhancing the performance of your Saatva mattress.
  • Eco-Friendly: Made with CertiPUR-US® foams and an organic cotton cover, this foundation is free of potentially harmful chemicals.
  • Durable Construction: Handcrafted from premium North American spruce, this foundation is built to last.
  • High Customer Satisfaction: With a 4.8-star rating and an A+ from the Better Business Bureau, Saatva has a track record of satisfied customers.
  • Financing Options: The availability of 0% APR financing makes it easier to invest in quality sleep.


  • Price: The foundation is on the higher end of the price spectrum, especially when adding the optional Universal Frame.
  • Limited Information: The lack of detailed information on foundation height options may require additional research.

How It Performed

The Saatva Classic Mattress Foundation is engineered to be stronger and more durable than a traditional box spring. It pairs seamlessly with any Saatva mattress, offering optimal support and a stable sleep surface. The use of CertiPUR-US® foams and an organic cotton cover ensures that your sleep setup is eco-friendly. Handcrafted in the U.S.A. from premium North American spruce, this foundation is built to last, protecting your mattress investment.

Bottom Line – Why It Makes the Cut

The Saatva Classic Mattress Foundation is a high-quality, eco-friendly alternative to traditional box springs. Its optimal support and durable construction make it an excellent investment for anyone looking to enhance their sleep experience. While the price may be a consideration, the financing options and current promotions make it more accessible. Overall, it’s a solid foundation that lives up to the Saatva brand’s reputation for quality and customer satisfaction.

4) Avocado Organic Latex Foundation

Avocado Organic Latex Foundation
Avocado Organic Latex Foundation

Price Range: $349

Foundation Type: Solid Wood

Height Options: Standard (7.25″), Low Profile (3.5″)


  • Solid Wood Construction: Ensures durability and longevity.
  • Eco-Friendly Certifications: GOTS, Greenguard, and Climate Neutral Certified.
  • Tool-Free Assembly: Hassle-free setup in just minutes.
  • 10-Year Warranty: A long-term commitment to quality and performance.


  • Shipping Time: Ready to ship in 3-7 weeks, which may be a bit long for some.
  • Price: At $349, it’s an investment in quality and sustainability.

Bottom Line – Why It Makes the Cut

The Avocado Organic Latex Foundation is more than just a bed base; it’s a commitment to eco-friendly, durable, and convenient living. With its solid wood construction and multiple certifications, this foundation not only supports your mattress but also your sustainable lifestyle.

Product Details

The Avocado Organic Latex Foundation is a versatile and eco-friendly bed foundation designed to offer robust support and optimal airflow for any mattress. It comes in two height options: a standard height of 7.25 inches and a low-profile height of 3.5 inches. Optional legs are available at 6.25 inches for those who prefer a standalone bed frame.

The foundation is crafted from solid wood and features a GOTS-certified organic cotton canvas exterior. It’s also GREENGUARD Gold Certified for low emissions, ensuring a healthier sleep environment.

Dimensions & Weights
  • Twin: 37.5″ W x 75″ L — 56 lbs.
  • Queen: 59.5″ W x 79″ L — 69 lbs.
  • King: 75.5″ W x 79″ L — 85 lbs.
  • GOTS Certified Organic Cotton
  • Greenguard Gold Certified
  • Climate Neutral Certified

How It Performed

Durability and Support

The Avocado Organic Latex Foundation is built to last, with a 10-year warranty to back it up. The solid wood frame and organic cotton canvas exterior provide a sturdy and durable structure that can support up to 600 pounds.

Airflow and Comfort

The wooden slats are spaced 3.25 inches apart, allowing for optimal airflow. This design ensures that your mattress remains fresh and free from moisture, extending its lifespan.

Ease of Assembly

One of the standout features is the tool-free assembly. The foundation can be set up in minutes, making it convenient for those who dread complicated assembly processes.

Eco-Friendly Credentials

The foundation is Climate Neutral Certified, meaning Avocado has taken steps to offset its carbon footprint. This aligns with the company’s broader mission to offer sustainable and responsible products.

What It’s Made Of

The foundation features a solid wood frame and a woven organic cotton canvas exterior. The slats are 2.5″ wide, placed 3.25″ apart, and 11/16″ thick, ensuring both durability and proper airflow.

Additional Perks

  • 1-Year Trial: Test out the foundation to make sure it’s the right fit for you.
  • In-Home Setup: If ordered with a mattress, Avocado offers optional in-home delivery and setup within the continental U.S.

The Avocado Organic Latex Foundation is a premium, eco-friendly choice for those looking to invest in a sustainable and durable bed foundation. Its solid construction, easy assembly, and eco-friendly certifications make it a standout option in a crowded market.


A good foundation should complement your mattress by providing stable support underneath it so that you can enjoy a comfortable night’s sleep. Considering what sets each foundation apart- whether affordability, modern amenities or sustainability – we have suggested four choices covering different requirements everyone may need.

When choosing which option suits best always consider our suggested criteria of compatibility with mattress sizes/weight capacity along with sturdiness/durability. A great foundation choice will enhance rather than detract from your entire sleeping experience, so choose wisely!


What is a foundation, and why do I need one for my memory foam mattress?

A foundation is the base that supports your mattress. A good foundation will provide stability, support, and even weight distribution to ensure that your mattress performs as intended. For memory foam mattresses, a solid foundation is critical to prevent sagging or uneven wear.

Are all foundations suitable for king memory foam mattresses?

No, not all foundations are suitable for king memory foam mattresses. When choosing a foundation, it’s important to consider factors such as weight capacity and support, as well as any specific requirements or recommendations from the manufacturer of your mattress. Generally speaking, a strong and sturdy platform bed with slats no more than 3 inches apart or an adjustable bed frame can be good options.

Can I use my existing box spring with a king memory foam mattress?

It depends on the condition of your existing box spring. If it’s in good shape and provides adequate support without sagging or other signs of wear and tear, then you may be able to use it with your new king-sized memory foam mattress. However, if your box spring is old or damaged in any way, it’s best to replace it with a new foundation that will provide better support and help extend the lifespan of your new mattress.

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