Best Mattress Firmness by Sleep Position and Body Weight (Chart)

Firmness Guide · Canada · Updated October 2026

Best Mattress Firmness by Sleep Position and Body Weight (Chart)

Written by Jordan Bedwell, Co-Founder at Hamuq Inc, and Artist Business Manager for Elyse Saunders. Based in Toronto, Ontario, Canada.

Reviewed by Nathan Nielson, Leadership at Hamuq focused on empowering teams, driving innovation, and delivering results through data-oriented decision-making. Based in Toronto, Ontario, Canada.

The right mattress firmness depends on two things above all: how you sleep and how much you weigh. This guide gives you a clear firmness chart that maps sleep position to body weight, explains the 1-to-10 firmness scale, and shows why the same mattress can feel different to different people. Use it as a starting point, then confirm the feel on a sleep trial. For the full buying guide, see the best mattress in Canada.

The 1-to-10 mattress firmness scale, from plush to extra firm. Most sleepers land in the 4 to 7 range.

The firmness scale, explained.

Firmness is measured on a scale of 1 to 10, where 1 is the softest and 10 is the hardest, and it describes how a mattress feels on the surface, not how supportive it is underneath. This is the single most misunderstood point about mattresses: firmness and support are different. A mattress can be soft and still supportive, or firm and still unsupportive. Firmness is about feel; support is about keeping your spine aligned.

The 1-to-10 scale is an industry convention, not a measurement. Each brand and review site assigns its own numbers, so a 6 from one company may not feel like a 6 from another. A European standard scale does exist, called H(s), and it runs the other way: 1.0 is the firmest and 10.0 the softest. It was the scale used in the 2003 trial in The Lancet listed in our sources. Some reviewers measure instead of rating: RTINGS, for example, reports firmness in pascals per millimetre. Treat any 1-to-10 number, including the ones on this page, as a description to test on a sleep trial.

In practice, almost no one wants the extremes. Very few sleepers are comfortable at a 1 or 2, which feels like sinking into a marshmallow, or at a 9 or 10, which feels like lying on the floor. The large majority of people are happiest somewhere between 4 and 7, and the chart below narrows that down by how you actually sleep.

How sellers describe their own firmness

These are each seller's own words about its own mattress, read on the dates shown. They are descriptions, not measurements, and one brand's medium-firm may not feel like another's.

The mattress firmness chart

This is the core of the guide. Find your sleep position across the top and your weight down the side, and the cell gives the firmness range that suits most people in that group. Treat it as a starting point, not a rule, because comfort is individual.

Our guide, not a measurement: general guidance by sleep position and body weight on the 1-to-10 convention. Ideal firmness is personal; a sleep trial is the reliable way to confirm your fit.

Firmness by sleep position

Your sleep position decides where your body presses into the mattress, which decides how much give you need there. This is the first thing to get right.

Side sleepers: softer, 4 to 6

Side sleeping concentrates your weight on the shoulder and hip, so you need a softer top layer that lets those points sink in while keeping the spine straight. Too firm, and the shoulder and hip are pushed out of alignment, which side sleepers often describe as numb arms or sore hips. A medium-to-medium-soft feel is the side sleeper's zone.

Back sleepers: medium-firm, 5 to 7

Back sleeping needs even support that fills the lumbar gap without letting the hips sink. Medium-firm is the classic back-sleeper range: firm enough to hold the lower back, with just enough give to follow the spine's natural curve. In one randomised trial of 313 adults with chronic non-specific low-back pain, those given medium-firm mattresses reported less pain in bed and less disability after 90 days than those given firm mattresses (Kovacs et al., The Lancet, 2003). That is one trial of one group of patients, and it is not medical advice.

Stomach sleepers: firmer, 6 to 8

Stomach sleeping is the position that most needs firmness, because a soft mattress lets the belly and hips sag, arching the lower back. A firmer surface keeps the hips level with the shoulders. If you sleep this way and wake with a sore lower back, check whether your hips are sinking below your shoulders, and ask a clinician about pain that persists.

Combination sleepers: medium, 5 to 6

If you change position through the night, aim for the middle. A medium feel is responsive enough to move on without feeling stuck, and versatile enough to work reasonably in every position. Look for a mattress that responds quickly rather than one you sink deep into.

Firmness by body weight

Weight is the factor most simple charts skip, and it changes everything, because firmness is a feel and a heavier body compresses a mattress more. The same mattress genuinely feels softer to a heavier person and firmer to a lighter one. This is why a couple with different builds can disagree so completely about the same bed.

Lighter sleepers, under about 130 lb (59 kg)

Lighter bodies do not sink into a mattress as far, so a medium-firm mattress can feel hard to them. Lighter sleepers generally want to go about one step softer than the baseline for their position, so the surface actually contours. A firm mattress that never gives is a common complaint for lighter people. Our guide for lightweight sleepers covers the picks.

Average sleepers, about 130 to 230 lb (59 to 104 kg)

This is the range most mattresses are designed and rated for, so the baseline recommendation for your sleep position usually applies directly. The chart figures in the average row are the default starting point.

Heavier sleepers, over about 230 lb (104 kg)

Heavier bodies compress a mattress more and sink further, so they generally want about one step firmer than the baseline, plus strong support underneath to avoid bottoming out. Support matters as much as surface firmness here: a heavier sleeper needs a mattress with a robust support core, which is where sturdy hybrids tend to suit better than soft all-foam beds.

Firmness for couples with different needs

When two people of different weights or sleep positions share a bed, the honest answer is compromise, and there are three realistic routes. The simplest is to meet in the middle at a medium-to-medium-firm feel, around 5 to 6, which works reasonably well for most pairings. The second is a mattress with good pressure relief and a responsive surface, which tends to satisfy a wider range of bodies than a very soft or very firm one.

The third route, if the mismatch is large, is a split-firmness setup or two toppers, though that adds cost and complexity. For most couples, a quality medium-firm mattress with a real trial is the practical answer, because the trial lets you both judge it at home rather than guessing in a showroom.

The cold-room factor Canadian sleepers should know.

One thing no firmness chart captures: temperature changes how firm a foam mattress feels. Comfort and memory foam get softer when warm and firmer when cold, so that the same mattress can feel a step harder in a cool Canadian bedroom or when it is first unboxed in winter than it will once it is warmed to body temperature. If a new mattress feels firmer than its rating suggests, the room temperature may be part of the reason. We cover this in detail in our guide on softening a too-firm mattress.

Where Hamuq sits on the firmness scale

The Original Hybrid ($999 CAD queen) is described on its product page as medium-firm, 6 out of 10, which lands in the sweet spot for back sleepers, combination sleepers, and average-weight side sleepers who want support with some give. The Organic Hybrid ($1,999 CAD queen) is firmer than the Original Hybrid and suits heavier sleepers, stomach sleepers, and anyone who prefers a firmer surface.

Because firmness is personal and shifts with weight and position, the number on the scale only gets you so far. Both Hamuq mattresses come with a 120-night trial, which is the real test: several weeks on the mattress in your own room tell you far more than any firmness rating can.

Possible downside: Hamuq does not currently offer a plush, sub-4 soft option, so a lighter side sleeper who wants a deep-sink, cloud-like feel may find even the Original Hybrid firmer than ideal, and could pair it with a soft topper or look elsewhere for that specific feel. Use the chart honestly against your own weight and position before deciding. Compare both in the Hamuq lineup.

Frequently asked questions

What mattress firmness is best for side sleepers?

Most side sleepers do best around 4 to 6 on the firmness scale, a medium-to-medium-soft feel. This lets the shoulder and hip sink in enough to keep the spine straight while still supporting the waist. Lighter side sleepers can go a step softer, and heavier side sleepers a step firmer for more support.

How does body weight affect mattress firmness?

Body weight changes how far you sink, so the same mattress feels softer to a heavier person and firmer to a lighter one. As a rule, lighter sleepers under about 130 lb should choose one step softer than the baseline for their position, and heavier sleepers over about 230 lb one step firmer, with strong support underneath. This is why weight matters as much as sleep position.

What is the best firmness for back pain?

Medium-firm, around 5 to 7, is the usual recommendation for back pain, not the firmest option. It supports the lower back while still following the spine's natural curve. The right point within that range shifts with your weight and position, and a sleep trial is the reliable way to confirm it.

Is a firmer or softer mattress better?

Neither is universally better; it depends on your sleep position and weight. Side sleepers generally need softer, stomach sleepers firmer, and back sleepers in between, with body weight shifting each of these. Firmness is distinct from support, so a good mattress provides the right feel and keeps your spine aligned.

What firmness is medium-firm on the scale?

Medium-firm is roughly 6 to 7 on the 1-to-10 firmness scale. It is the most popular range because it suits the widest set of sleepers, offering support with a little give. Both the sweet spot for back and combination sleepers and a safe default when you are unsure, medium-firm is where many mattresses, including the Hamuq Original Hybrid, are built.

Why does my mattress feel firmer than its rating?

A few reasons: a new mattress is at its firmest before it breaks in, a cool room stiffens the foam so the bed feels harder than its rating suggests, and your body may be adjusting to an older, softer mattress. Give a new mattress a few weeks, warm the room, and the feel usually settles closer to its rated firmness.

Is the 1 to 10 mattress firmness scale a standard?

No. The 1-to-10 scale that mattress brands use, where 1 is the softest and 10 the firmest, is a convention, and each brand or review site assigns its own numbers. A European standard scale called H(s) does exist and runs the other way, from 1.0 for the firmest to 10.0 for the softest; it was used in a 2003 trial published in The Lancet. A brand's 6 out of 10 is therefore its own description, not a measurement against that standard.

How this chart was built

• The chart and the band table are our guide. They set out how firmness, sleep position and body weight interact, as explained above. They are not test results and no laboratory measured them.
• Research. One randomised trial is cited (Kovacs et al., 2003). It compared firm and medium-firm mattresses in adults with chronic low-back pain. It did not test sleep positions, body weight bands or any mattress sold in Canada today.
• Seller descriptions. The firmness words in the seller table are each seller's own, read on the dates shown. We did not test those mattresses.
• Hamuq. Figures for our own mattresses come from Hamuq's product pages and FAQ, read 13 October 2026.
• Units. Weights are shown in pounds and kilograms, rounded to the nearest kilogram.

The bottom line

Start with your sleep position, then adjust for your weight: side sleepers, softer at 4 to 6; back sleepers, medium-firm at 5 to 7; stomach sleepers, firmer at 6 to 8, with lighter sleepers going a step softer and heavier sleepers a step firmer. Remember that firmness is a personal feel, separate from support, and that a cold room can make any foam mattress feel harder. Use the chart as your starting point, then confirm with a sleep trial. To put it into practice, compare the Original Hybrid with the full lineup of best mattresses in Canada.

About the authors

Written by Jordan Bedwell, Co-Founder at Hamuq Inc, and Artist Business Manager for Elyse Saunders. Based in Toronto, Ontario, Canada.

Reviewed by Nathan Nielson, Leadership at Hamuq focused on empowering teams, driving innovation, and delivering results through data-oriented decision-making. Based in Toronto, Ontario, Canada.