The Scale is Narrower Than You Think
Logic suggests mattresses are evenly distributed from 1 to 10. They aren't.
A 1/10 is essentially a bean bag, and a 10/10 is a concrete floor. Neither offers a good night's sleep. The functional world exists almost entirely between3.5 (Soft) and 9 (Firm). (See our How to Choose a Mattress guide for more nuance.)
"The sweet spot for human spinal alignment is surprisingly small."
Hover over the bars to see real-world equivalents.
The Myth of "Universal Comfort"
If you are paralyzed by choice, you are statistically safe aiming for a 6 out of 10.
Why 6 is the Magic Number
Our data shows that a "Medium-Firm" mattress (rated 6/10) is the ideal firmness for approximately 85% of all sleepers.
- Pressure Relief: Provides enough sinkage to cradle hips and shoulders.
- Spinal Support: Provides enough pushback to keep the spine aligned.
- The Geometric Compromise: Accommodates the widest variety of positions.
The Goldilocks
Firmness Calculator
Firmness is relative to your mass. A "Medium" mattress feels firm to a light person but soft to a heavy person. Use our algorithm to find your adjusted needs.
Recommended Firmness
Medium
The classic Goldilocks zone. You sink enough for pressure relief but are supported by the core layers.
Support ≠ Firmness
This is the most common misconception. We equate "Hard" with "Supportive," but they are distinct metrics involving different layers of the mattress.
Firmness (The Feel)
Immediate Sensation
Determined by the top Comfort Layers (Foam, Pillow top).
It defines how much the mattress "hugs" your body (sinkage). A soft mattress hugs you; a firm mattress floats you.
Support (The Alignment)
Structural Integrity
Determined by the bottom Support Core (Coils, High-density foam).
It defines the ability to keep your spine in a neutral line. You can have aSoft mattress with excellent Support.
Visualizing The Layers
Key Takeaway
The perfect mattress isn't about finding the "best" model, but finding the right mathematical match for your body. Use the calculator above as your starting point, and remember that "Universal Comfort" is a myth.