Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service levels, popularity trends, and more. The rankings reflect our opinion and should be a good starting point for shopping. By purchasing the products we rank, you’ll get the lowest price we found while we may receive a commission at no cost to you, which will help us continue to provide you with value.
Advertising Disclosure
10 Best firm mattress in a box kings of 2026
Save up to 38% off
1
MLILYEGOHOME 14 inch Firm King Mattress, Memory Foam Mattress with Cooling Cover, Bed in a Box, CertiPUR-US Certified, Breathable and Supportive, Made in USA, 76''x80''x14'' Black
Key specs-
top style:Cooling cover
-
size:14 inches
-
construction:Copper-Infused AEROFUSION
-
fill material:Memory foam
-
dimensions:80 x 76 x 14 inches
9.9Exceptional
Our Rating
-
-
Powerful technology We scan thousands of products and stores, analyzing reviews to find what matters most to users like you
Careful review Our team ensures quality, value, and fit based on real user feedback
Trusted insights AI and human analysis guide your decisions, reflecting real user prioritiesReal users impact
Thousands of users trust our site daily
- Based on millions of stores and reviews
- Shoppers influence our rankings
Analyzing top stores
2
SleepmaxSleepmax Firm King Size Mattress 14 Inch - Extra Firm Deep Sleep Hybrid Mattresses King Pain Relief - Cooling Bed in a Box for Back & Side Sleepers - 365-Night Trial, Forever Warranty, Fiberglass-Free
17% Off9.8Exceptional
-
3
AGHODTKing Mattress, 14 Inch King Size Hybrid Mattress in a Box, Medium Firm Memory Foam mattress, with Individual Pocket Springs, Upgrade Zoned Support, Motion Isolation&Pressure Relief, CertiPUR-US
38% Off9.5Excellent
-
4
AyeawoAyeawo Firm King Size Hybrid Mattress 12 Inch, Bed in a Box with Pocket Spring, Gel Memory Foam, Pressure Relief & Lumbar Support, Cooling Feel, CertiPUR-US Certified, 365 Night Trial
20% Off9.4Excellent
-
5
LETMOONLETMOON Firm King Size Mattress [New Version], 12 Inch Gel Memory Foam Hybrid Mattress King Bed in a Box, Pressure & Pain Relief, CertiPUR-US, Individual Pocket Spring, Edge Support
9.3Excellent
-
-
See Today’s Deals & Prices
6
VISCOFLEXVISCOFLEX Extra Firm King Mattress 14 Inch, Hybrid Mattress Extra Lumbar Support Pain Relief, No Sagging Bed Mattresses in a Box - 365-Night Trial, CertiPUR-US, Hotel Collection
24% Off9.1Excellent
-
7
MLILYMLILY EGOHOME 12 Inch King Memory Foam Mattress for Back Pain, Cooling Copper Gel Bed in a Box, Foam Made in USA, CertiPUR-US Certified, Therapeutic Medium Firm, 76x80x12 Black
Key specs-
top style:Cooling Gel Memory Foam
-
size:King
-
construction:Graphene Technology Cover
-
fill material:Memory Foam
-
dimensions:80 x 76 x 12 inches
8.8Very Good
-
8
BedStoryBedStory Extra Firm King Mattress 14 Inch, Hotel Collection Hybrid Mattresses with Zoned Lumbar Support, Extra Back & Hip Support, CertiPUR-US, Fiberglass-Free, 365-Night Trial
25% Off8.6Very Good
-
9
BedStoryBedStory Firm King Mattress 14 Inch - Deep Sleep Hybrid Mattresses 7-Zone Pain Relief - Firm Bed in a Box - Fiberglass Free, CertiPUR-US Certified, 365-Night Trial,10 Years Warranty
8.5Good
-
10
BEDinglyBEDingly King Size Mattress, 12 Inch Luxury Hybrid King Mattress in a Box, Medium Firm Mattresses with Cooling Gel Memory Foam & Pocket Springs, Double Additional Support, 365-Night Trial
23% Off8.3Good
-
