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Mattress firmness is one of the most important — and most misunderstood — factors in choosing a mattress. The right firmness level depends on your sleep position, body weight, and personal preference. This guide explains every level of the firmness scale and who each suits best.
The Firmness Scale: 1–10
Mattress firmness is typically rated on a 1–10 scale, where 1 is extremely soft and 10 is extremely firm. Most mattresses fall in the 3–8 range, with the sweet spot for most sleepers around 5–7 (medium to medium-firm).
Soft (1–3): Plush and Sinking
Soft mattresses allow significant sinking and contouring. They’re best for: strict side sleepers who need deep shoulder and hip cushioning, lighter sleepers (under 130 lbs) who don’t compress firmer foams enough, and those with severe joint pain or arthritis. Not recommended for stomach sleepers or back sleepers over 200 lbs.
Examples: Helix Sunset, Saatva Plush Soft, Nectar in soft configuration.
Medium-Soft (3–4): Gentle Contouring
Medium-soft provides significant cushioning with slightly more support than pure soft. Popular with side sleepers of average weight and some back sleepers who like a plush feel. Hits the sweet spot for many couples where one partner is a side sleeper.
Medium (5): The Universal Feel
Medium firmness is the most popular in the industry because it suits the widest range of sleepers. Works reasonably well for side, back, and combination sleepers of average weight. The Casper Original and Tuft & Needle Original both target medium firmness. It’s the safe choice if you’re unsure.
Medium-Firm (6–7): The Most Recommended
Medium-firm is recommended by chiropractors and sleep specialists for most adults for optimal spinal alignment. It provides enough cushioning for side sleepers while offering adequate support for back sleepers. The Helix Midnight and WinkBed Luxury Firm fall here.
Firm (7–8): Flat Support
Firm mattresses provide minimal sinking, keeping the sleep surface relatively flat. Ideal for stomach sleepers who need to keep hips from sinking, heavier back sleepers (200+ lbs), and those with specific back conditions requiring a flat sleeping surface.
Extra Firm (9–10): Maximum Support
Extra firm mattresses are rarely sold by mainstream brands — they feel like sleeping on a firm floor. Occasionally prescribed for specific orthopedic conditions. Not recommended for most consumers.
How Body Weight Affects Firmness
A 120 lb person on a medium mattress will experience it as medium-firm; a 250 lb person on the same mattress will experience it as medium-soft. Always consider your weight when interpreting firmness ratings. Heavier sleepers should add 1–2 numbers to any firmness rating to approximate their experience.
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