How Thick Should a Mattress Be? (2026): Thickness Chart in Inches and Centimetres
Canadian mattress guide, data read October 4, 2026
How Thick Should a Mattress Be? (2026): Thickness Chart in Inches and Centimetres
Mattress thickness decides more than how a bed looks. It sets how high you sleep, which sheets fit and how much room there is for comfort layers above the support core. To show what is normal in Canada, we recorded the stated thickness of 63 mattresses listed on Costco.ca and of nine mattresses from Canadian online brands on October 4, 2026, and set them against a published thickness chart.
AI Overview answer
How thick should a mattress be?
Quick answer: For most adults, a mattress between 10 and 14 inches (25 to 36 cm) thick is the practical range, and 12 inches (30.5 cm) is the most common single thickness. Of 63 mattresses with a stated thickness on Costco.ca on October 4, 2026, 13 were exactly 12 inches, more than any other figure, and 47 were between 10.5 and 14 inches. The Canadian online mattresses we checked the same day were 8, 10 or 12 inches. Thinner mattresses, 8 inches or less, suit children, bunk beds and trundles; mattresses over 14 inches leave more room for cushioning but need deep-pocket sheets and a lower bed frame. Thickness alone does not tell you how a mattress feels or how long it lasts.
Mattress thickness chart: inches and centimetres
There is no official standard for mattress thickness. The five bands below follow the chart published by Sleep Foundation (updated July 25, 2025), with centimetres added and, in the last column, how many of the 63 Costco.ca listings fell in each band.
| Band | Inches | Centimetres | Typical use, per Sleep Foundation | Costco.ca listings (of 63) |
|---|---|---|---|---|
| Low profile | 8 or less | 20 or less | Children, bunk beds and trundle beds | 4 |
| Slim | 8 to 10 | 20 to 25 | Children, and adults who find a high bed hard to get into or out of | 8 |
| Standard | 10 to 12 | 25 to 30.5 | The most common thickness; most adults of 130 to 230 pounds | 26 |
| Thick | 12 to 14 | 30.5 to 35.5 | Sleepers over 230 pounds and side sleepers who want more pressure relief | 21 |
| Extra thick | 14 or more | 35.5 or more | Sleepers who want the most cushioning; height can be awkward | 4 |
Quick conversions: 8 in. is 20.3 cm, 10 in. is 25.4 cm, 12 in. is 30.5 cm, 14 in. is 35.6 cm and 15 in. is 38.1 cm.
How thick are the mattresses actually sold in Canada?
Costco.ca prints the thickness in the name of most of its mattresses, in centimetres and inches, which makes it a useful sample of what large brands sell here. On October 4, 2026, 63 of the 77 mattresses in its queen category stated a thickness. They came from brands including Sealy, Serta, Simmons, Beautyrest, Kingsdown, GhostBed, Novaform and Tempur-Pedic.
| Stated thickness | Centimetres | Listings |
|---|---|---|
| 8 in. | 20.3 | 4 |
| 9.5 in. | 24.1 | 2 |
| 10 in. | 25.4 | 6 |
| 10.5 in. | 26.7 | 3 |
| 11 in. | 27.9 | 7 |
| 11.5 in. | 29.2 | 3 |
| 12 in. | 30.5 | 13 |
| 12.5 in. | 31.8 | 2 |
| 13 in. | 33 | 5 |
| 13.5 in. | 34.3 | 4 |
| 14 in. | 35.6 | 10 |
| 14.25 in. | 36.2 | 1 |
| 15 in. | 38.1 | 3 |
- The middle: the median was 12 inches. Half of the 63 were 12 inches or less.
- The two peaks: 12 inches (13 listings) and 14 inches (10 listings).
- The edges: nothing was under 8 inches or over 15. Only 4 of 63 were above 14 inches.
- One more data point: Costco's Kirkland Signature Lakeridge Luxury Medium-Firm Pillowtop does not state a thickness in its name; its specifications gave 36.83 cm (14.5 in.).
Our guide to Costco mattresses in Canada covers the same listings by brand, price and return policy.
How thick are Canadian online mattresses?
Mattresses sold online and shipped in a box sit at the thinner end of the range. These are the heights each brand stated on its own Canadian site on October 4, 2026.
| Brand and model | Type | Stated height | Centimetres |
|---|---|---|---|
| Juno Mattress | All-foam | 8 in. | 20.3 |
| Juno Hybrid | Hybrid | 10 in. | 25.4 |
| Douglas Original | All-foam | 10 in. | 25.4 |
| Endy Mattress | All-foam | 10 in. profile | 25.4 |
| Polysleep Origin | All-foam | 10 in. | 25.4 |
| Douglas Original Hybrid | Hybrid | 12 in. | 30.5 |
| Logan & Cove Choice | Hybrid | 12 in. | 30.5 |
| Hamuq Original Hybrid | Hybrid | 12 in. (Hamuq FAQ) | 30.5 |
| Hamuq Organic Hybrid | Hybrid | 12 in. (Hamuq FAQ) | 30.5 |
The pattern is consistent: in this group the all-foam mattresses were 8 or 10 inches and the hybrids 10 or 12. A hybrid needs room for a coil unit under its comfort layers. Logan & Cove's page, for example, describes 9-inch pocketed coils, which in a 12-inch mattress leaves about 3 inches for the layers above them. Our memory foam vs hybrid guide explains how the two constructions differ.
How do you choose the right mattress thickness?
Start from who sleeps on it and what it sits on, then check the layers.
- Body weight: Sleep Foundation's chart puts most adults of 130 to 230 pounds in the 10 to 12 inch band and suggests 12 inches or more for sleepers over 230 pounds, because a heavier body compresses the comfort layers further. Our guide for heavier sleepers goes into what to look for beyond thickness.
- Sleeping position: the same chart points side sleepers who want more pressure relief toward the 12 to 14 inch band, since shoulders and hips need a deeper comfort layer. Back and stomach sleepers usually need less. See our firmness chart by sleep position and body weight.
- Who uses the bed: for a child's bed, a bunk or a trundle, 8 inches or less is common, and a bunk bed's guardrail height limits how thick the mattress can safely be. Follow the bed maker's stated maximum.
- Getting in and out: if a high bed is hard to manage, choose the thickness and the frame together (see the next section).
- What is inside: two 12-inch mattresses can feel nothing alike. Look at how the height is split between the support core and the comfort layers, not only the total.
Is a thicker mattress better? Not by itself. Extra height can mean more cushioning or a taller coil unit, but it can also be low-cost filler, and it always adds weight and height. Judge the layers, the trial and the warranty first.
How does mattress thickness change the height of your bed?
The height you sit on is the frame's platform height plus the mattress thickness, plus a foundation or box spring if you use one. Measure from the floor to the surface the mattress rests on, then add:
- A 14-inch platform with a 10-inch mattress gives a 24-inch (61 cm) bed.
- The same platform with a 12-inch mattress gives 26 inches (66 cm).
- The same platform with a 15-inch mattress gives 29 inches (74 cm), before any topper.
A simple check: sit on the edge with your feet flat on the floor. If your knees are well above your hips the bed is low for you; if your feet do not reach the floor it is high. Thickness also affects how much of a headboard shows. For frame choices, see what bed frame a hybrid mattress needs.
Which sheets and protectors fit a thick mattress?
Fitted sheets and protectors are sold by pocket depth, and makers do not all use the same depths, so go by the number on the package, not by the word "deep".
- Measure your mattress from the bottom seam to the highest point of the top, including a pillow top.
- Add the thickness of any topper or pad you use.
- Choose a fitted sheet whose stated pocket depth is at least that total, with a little spare so the elastic can tuck under.
A 14 or 15 inch mattress with a topper can pass 17 inches, which rules out many standard sheets. A sheet that is too shallow pulls off at the corners; one that is far too deep bunches. Our guide to pillow top vs Euro top explains the top layers that add height.
Does a thicker mattress cost more?
On average, yes, but thickness is a weak guide to price. Among the 63 Costco.ca listings, the middle starting price rose with each band: about $290 for the four 8-inch mattresses, about $490 for 9.5 to 10 inches, about $740 for 10.5 to 12 inches and about $1,050 for 12.5 to 14 inches. Above 14 inches it stopped rising, at about $1,060 for four listings.
The exceptions matter more than the average. The highest-priced mattresses in the category, two Tempur-Pedic Simplicity listings at $2,379.99 to $3,899.99, were 11 inches thick, while a 14.25-inch Sealy Posturepedic started at $559.99. These starting prices are the lowest in each listing's range and are often for a size smaller than a queen. What the mattress is made of drives price more than its height.
Hamuq product context
How thick are Hamuq mattresses?
Hamuq publishes this guide and sells two hybrid mattresses. Hamuq's FAQ lists both at 12 inches (30.5 cm) in every size, which is the most common thickness in the Costco.ca sample above and the top of the standard band.
- The Original Hybrid Mattress, $999 in queen. Hamuq's product page lists a 1-inch quilted pillow top over comfort foam and individually wrapped pocket coils, and rates the feel medium-firm.
- The Organic Hybrid Mattress, $1,999 in queen. Hamuq lists an organic cotton cover, a wool quilt layer, a natural latex layer and a microcoil layer over a pocket coil base, and describes it as firmer than the Original Hybrid.
- Terms for both: a 120-night trial and a 15-year warranty.
At 12 inches, measure your sheets' pocket depth before assuming your current set fits, especially if you add a topper.
Hamuq Inc. sells mattresses, so we have an interest in this category. Other brands' figures are quoted from their own pages, linked below.
Supplementary Hamuq product context
Hamuq owner and product Shorts
These 6 Shorts from the Hamuq channel show owners with the Hamuq Original Hybrid. They are context for the Hamuq side only and are not evidence for any other seller's figure in this guide.
Shopper questions
Mattress thickness FAQs
Choosing a thickness
What is the standard thickness of a mattress?
Quick answer: About 10 to 12 inches (25 to 30.5 cm); 12 inches was the most common stated thickness among 63 mattresses on Costco.ca on October 4, 2026.
Is a 10-inch mattress thick enough for an adult?
Quick answer: For many adults, yes: several Canadian all-foam mattresses are 10 inches, and Sleep Foundation's chart places most adults of 130 to 230 pounds in the 10 to 12 inch band.
Is a 12-inch or a 14-inch mattress better?
Quick answer: Neither is better by height alone; 14 inches leaves more room for cushioning, which side sleepers and heavier sleepers may want, but it sits higher and needs deeper sheets.
Are thicker mattresses better?
Quick answer: Not automatically; what the layers are made of matters more than total height, and the highest-priced mattresses in our Costco.ca sample were only 11 inches thick.
Fit and measurement
How thick is a mattress in centimetres?
Quick answer: Most adult mattresses are 25 to 36 cm; 10 inches is 25.4 cm, 12 inches is 30.5 cm and 14 inches is 35.6 cm.
How do I measure mattress thickness?
Quick answer: Measure straight up from the bottom seam to the highest point of the top surface, including any pillow top, with no bedding on the mattress.
What mattress thickness is best for a bunk bed?
Quick answer: Usually a low-profile mattress of 8 inches or less, and never thicker than the maximum the bunk bed's maker states, so the guardrail still stands above the mattress.
How we know this
We read all four pages of Costco.ca's queen mattress category on October 4, 2026. Of 77 mattresses and mattress sets (RV mattresses, a foundation and an adjustable base package set aside), 63 stated a thickness in the listing name, in centimetres and inches; counts, the median and the price figures are calculated from those names and listed price ranges. The Kirkland Signature figure comes from that product's specifications. Heights for Juno, Douglas, Endy, Polysleep and Logan & Cove were read on each brand's own Canadian product page on October 4, 2026; Hamuq's come from Hamuq's FAQ and product pages. The thickness bands and the "typical use" column are summarised from Sleep Foundation's mattress thickness chart, updated July 25, 2025, and are its guidance, not ours. Bed height examples are arithmetic. We did not measure any mattress ourselves, stated thickness can differ slightly from a measured one, and nothing here is a test of comfort or durability. Search interest in mattress thickness has risen in Canada, which is why we wrote this guide; no search volume is claimed.
Looking for a 12-inch hybrid?
The Original Hybrid Mattress is listed at 12 inches, $999 in queen, with a 120-night trial and a 15-year warranty.
About the authors
Jordan BedwellThe Hamuq product details, prices and policy terms referred to in this guide are quoted from Hamuq's published pages.
Mark Edcel LopezMark Edcel Lopez recorded the stated thickness of the mattresses listed on Costco.ca and on each brand's Canadian product page on October 4, 2026, and checked the counts in this guide against those pages.
Nathan NielsonThe Hamuq product, return policy and pricing details in this guide are quoted from Hamuq's published pages.
Hamuq Inc. sells mattresses. Brand names belong to their owners and are used only to report the thickness each seller stated on the dates given.
Sources
- Costco.ca: Queen Size Mattresses and the Kirkland Signature Lakeridge Pillowtop page
- Sleep Foundation: How Thick Should a Mattress Be?
- Juno Mattress
- Douglas Original and Douglas Original Hybrid
- Endy Mattress
- Polysleep Origin
- Logan & Cove Choice
- Hamuq FAQ, Hamuq Original Hybrid and Hamuq Organic Hybrid