Article: Mattress Firmness Guide: How to Choose Between Firm, Medium and Plush
Mattress Firmness Guide: How to Choose Between Firm, Medium and Plush
Firmness is the first thing people ask about and the thing most people get wrong. Firm does not mean supportive, soft does not mean unsupportive, and the right answer depends on how you sleep and how much you weigh. Here is the scale we use on every product page, what each step means, and how to find yours.
Support and firmness are not the same thing
Support is what keeps your spine in a straight line. It comes from the core of the mattress: the coils or the base foam. Firmness is how the top of the bed feels when you lie on it. A plush bed with a strong core is supportive. A firm bed with a broken-down core is not. So the question is never "firm or soft?" on its own. It is "which surface feel keeps my spine straight in the position I sleep in?"
The Rimrock feel scale
Every mattress on our site carries one of these feels. They line up across the house line, Helix and MOLECULE so you can compare.
- Firm. A solid surface with no soft top. You sleep on it, not in it. Studio Firm, Cottage Firm, Craftsman Gel Firm, Loft Firm, MOLECULE Reflex 11.
- Medium-firm. Support first, with a little give. Helix Dusk Luxe, MOLECULE Core 10, MOLECULE Engage Hybrid 12.
- Medium. The middle of the road and the feel that suits the most people. Studio Medium, Cottage Medium, Bungalow Medium, Loft Medium, Helix Midnight Luxe, Helix Midnight Elite, MOLECULE Reflex Pro 12, MOLECULE Engage Pro Hybrid 13.
- Plush. A cushioned top layer over a supportive core. Euro tops and pillow tops live here: Studio Euro Top, Cottage Euro Top, Craftsman Gel Euro Top, Craftsman Jumbo Pillow Top, Bungalow Jumbo Pillow Top, MOLECULE Reflex Elite Hybrid 14.
- Soft and luxe plush. The deepest cushion we sell. Loft Soft, Helix Sunset Luxe, MOLECULE Engage Elite Hybrid 14.
Start with your sleep position
- Back sleepers usually do best on medium-firm to medium. The bed needs to fill the curve of the lower back without letting the hips drop.
- Stomach sleepers need the firmest end. A soft bed lets the hips sink and arches the lower back all night.
- Side sleepers need give at the shoulder and hip, so medium, plush or soft. Read our side sleeper guide.
- Combination sleepers who move around usually land on medium. It is the feel that works acceptably in every position.
Then adjust for body weight
Heavier sleepers sink further into any surface, so a bed that reads medium to a lighter person can feel plush to them. If you are on the heavier side, shift one step firmer than your position suggests. Lighter sleepers do the opposite: they do not sink in enough to activate a firm surface, so a step softer usually feels better and still supports them.
Sharing the bed?
Medium is the compromise that works for most couples, because it supports the back sleeper without punishing the side sleeper. Our couples guide goes into motion transfer and size.
The five-minute test
Pressing on a bed with your hand tells you nothing. Lie down in the position you actually sleep in and stay there for five minutes. Then check three things: is there pressure building at your shoulder or hip, are your hips sinking below your shoulders, and does your lower back feel held or left hanging? If all three feel right, that is your feel. Do this on a firm, a medium and a plush in the showroom and the answer is usually obvious.
Buying online? Every bed we sell has a sleep trial, so the test happens at home over the first few weeks instead of in the store.
Every mattress we sell comes with a sleep trial: 100 nights on the Rimrock house line and MOLECULE, 120 nights on Helix. Shipping is free anywhere in the lower 48, in-store pickup is free, and local delivery is free within 100 miles of the store. Full details are in our shipping policy and trials and returns.
Not sure which one fits you? Ask a Pro: call 406-661-5704 or stop by the Billings showroom. No pressure, no commission, just a straight answer.
Rimrock Mattress
547 S 20th St W, Unit 10, Billings, MT 59102
406-661-5704
Monday to Friday 8 AM to 5 PM, Saturday 10 AM to 3 PM, Sunday closed
Frequently asked questions
Is a firmer mattress better for you?
No. The right firmness is the one that keeps your spine straight in your sleep position. For a side sleeper that is usually medium to plush. For a stomach sleeper it is firm.
What is the most popular mattress firmness?
Medium. It works for the most positions and the most couples, which is why the medium version of each line is the one we sell most.
Can I change my mind after buying?
Yes. Every mattress comes with a sleep trial: 100 nights on the house line and MOLECULE, 120 nights on Helix. See our trials and returns policy for the details.
