Mattress Depth: Standard Thickness, Deep Mattresses and Total Bed Height
How thick a mattress normally is, what counts as deep, and how depth changes the height of the bed, the sheets you need and what fits on bunk beds, cribs and adjustable bases.
A standard mattress is 10 to 14 in (25 to 36 cm) deep, with 12 in (30 cm) the most common thickness. Low-profile mattresses are 5 to 8 in (13 to 20 cm), and a deep mattress is about 14 to 18 in (36 to 46 cm), which includes most pillow tops and luxury hybrids.
- Most common
- 12 in (30 cm)
- Standard range
- 10–14 in (25–36 cm)
- Deep / pillow top
- 14–18 in (36–46 cm)
- Crib maximum
- 6 in (15 cm)
On this page
Standard mattress depth chart
Depth (also called thickness, height or profile) is measured from the bottom surface to the top of the mattress, at the side. It is independent of width and length: a twin and a king from the same line share the same depth.
| Profile | Inches | Centimeters | Where you find it |
|---|---|---|---|
| Ultra-low | 2–5 in | 5–13 cm | Cots, folding beds, camping pads |
| Low profile | 5–8 in | 13–20 cm | Bunk beds, trundles, daybeds, RVs, children's beds |
| Standard | 9–11 in | 23–28 cm | Budget foam and innerspring, guest beds |
| Standard (most common) | 12 in | 30 cm | The default for mid-range foam and hybrid lines |
| Thick | 13–14 in | 33–36 cm | Hybrids, premium foam |
| Deep | 15–18 in | 38–46 cm | Pillow tops, Euro tops, luxury hybrids |
| Extra deep | 18–22 in | 46–56 cm | A few luxury models; raised air beds |
There is no regulation for adult mattress depth, so the labels above are bedding-industry convention. What matters in practice is the number in the product specification, rounded up to the next inch.
Mattress depth by type
Construction largely sets the depth. A mattress needs a support core (coils or dense foam, usually 6 to 8 in) plus comfort layers on top, and adding comfort layers is the usual way manufacturers add depth.
| Type | Typical depth | Notes |
|---|---|---|
| Innerspring | 8–12 in (20–30 cm) | Thin comfort layer over a coil unit |
| Memory foam | 8–14 in (20–36 cm) | 10 and 12 in are the most common |
| Latex | 6–13 in (15–33 cm) | Often built from stacked 3-in layers |
| Hybrid | 11–15 in (28–38 cm) | Pocketed coils plus 3–5 in of foam or latex |
| Pillow top / Euro top | 14–18 in (36–46 cm) | The top adds 2–4 in to the base |
| Futon | 6–8 in (15–20 cm) | Must stay thin enough to fold |
| Crib and toddler | 4–6 in (10–15 cm) | Federal limit of 6 in |
| Air mattress | 8–22 in (20–56 cm) | Single-height or raised |
A pillow top is sewn on and a Euro top is sewn flush with the sides, but both are measured the same way: to the highest point of the top. Inflatable beds are covered in the air mattress size guide.
Where depth is limited for safety
Two federal rules limit mattress thickness, because a thicker mattress raises the sleeper relative to the rails that keep them in.
- Cribs: a full-size crib mattress must be no more than 6 in (15 cm) thick under the US crib mattress standard (16 CFR Part 1241). A thicker or added soft layer reduces the height of the crib side above the baby. Never add a topper to a crib mattress. Crib and toddler bed dimensions are in the crib size guide and the toddler bed guide.
- Bunk and loft beds: the bunk bed rules (16 CFR Part 1513, based on ASTM F1427) require the top of the upper bunk's guardrails to sit at least 5 in (12.7 cm) above the mattress surface, and the bed must carry a label stating the mattress size and maximum thickness. Use that label, not a general guide, to pick the top mattress. On many frames it allows only 6 to 8 in.
Moving a 10 or 12-in mattress from a regular bed to the top bunk can leave the guardrail barely above the sleeper. If the label says 8 in maximum, an 8-in mattress plus a 2-in topper already breaks the limit.
How mattress depth sets your bed height
The height people actually feel is the top of the mattress above the floor. For most adults, 20 to 25 in (51 to 64 cm) is easy to sit on and stand up from, which is close to knee height. Add the parts together to see where you will land:
| Setup | Calculation | Top of mattress |
|---|---|---|
| Floor-level platform + 10 in foam | 4 + 10 | 14 in (36 cm) |
| Platform bed + 12 in mattress | 12 + 12 | 24 in (61 cm) |
| Metal frame + low-profile foundation + 12 in | 7 + 5 + 12 | 24 in (61 cm) |
| Metal frame + standard box spring + 12 in | 7 + 9 + 12 | 28 in (71 cm) |
| Storage platform + 16 in pillow top | 14 + 16 | 30 in (76 cm) |
The fix for a bed that ends up too tall is usually the foundation, not the mattress. Swapping a 9-in box spring for a 5-in low-profile one drops the bed 4 in without changing the sleeping feel. Frame and foundation heights are listed in the bed frame size guide.
Depth also moves everything around the bed. A 16-in mattress covers 4 more inches of headboard than a 12-in one, and nightstands look and work best when their top sits within a few inches of the mattress top. See the nightstand heights in the bedroom furniture guide.
Matching sheets and toppers to mattress depth
Fitted sheets list a pocket depth. The pocket must be at least the mattress depth plus any topper, with 1 to 2 in to spare so the elastic wraps under the bottom edge.
| Mattress plus topper | Pocket you need | Sold as |
|---|---|---|
| Up to 12 in (30 cm) | 13–14 in | Standard pocket |
| 13–14 in (33–36 cm) | 15–16 in | Deep pocket |
| 15–17 in (38–43 cm) | 17–18 in | Deep pocket (check the number) |
| 18–22 in (46–56 cm) | 20–24 in | Extra-deep pocket |
A 12-in mattress with a 3-in topper is a 15-in stack and already needs a deep-pocket sheet. A 2-in topper on a 14-in hybrid needs 17 to 18 in. Pocket sizes for each sheet size are on the bed sheet size chart, and topper thicknesses on the mattress topper guide.
Comforters and blankets also lose side drop as depth increases. A queen comforter that hangs 15 in over each side covers a 12-in mattress with 3 in to spare, but on an 18-in pillow top it stops 3 in above the bottom edge.
Picking a depth
Thinner (6–10 in) suits
- Children, bunk beds and trundles
- Lighter adults and back or stomach sleepers who like a firm surface
- Adjustable bases, daybeds and RV platforms
- Anyone who needs a lower bed
Thicker (12–16 in) suits
- Side sleepers, whose shoulders and hips sink further
- Heavier sleepers, who can compress thin comfort layers down to the core
- Shorter platform frames that need height added
- People who want firm edge support for sitting
Most adjustable bases work with mattresses of roughly 8 to 14 in; thick innerspring and pillow-top models flex poorly. Check the base's stated range before you combine the two.
How to measure mattress depth
- Strip the bed. Remove the topper and mattress pad and measure them separately.
- Measure at the side, not the middle. Hold a straight edge flat across the top and measure down the side to the bottom seam. The center may be compressed by body impressions.
- Include the pillow top. Measure to its highest point.
- Allow for new foam. A boxed mattress can take 24 to 72 hours to reach its full depth after unrolling.
- Round up. A 12.5-in reading means 13-in sheets and pocket calculations.
Width and length for every bed size, plus international sizes, are in the mattress size chart.
Frequently asked questions
How deep is a deep mattress?
Bedding makers treat anything over about 14 in (36 cm) as deep. Deep mattresses usually measure 15 to 18 in (38 to 46 cm), and a few luxury pillow tops reach 20 in. They need deep-pocket fitted sheets.
How thick is a pillow top queen mattress?
A pillow-top queen is typically 14 to 18 in (36 to 46 cm) deep. The sewn-on top adds 2 to 4 in to a 10 to 14 in base. Measure at the highest point of the top, not at the seam below it.
Is a 10-inch mattress thick enough?
For most adults on a queen or smaller, yes. A 10-in mattress usually has a 6 to 7 in support core and 3 to 4 in of comfort layers. Heavier sleepers and side sleepers who sink further often prefer 12 in or more so they do not feel the core.
Does mattress depth change the length and width?
No. A 10-in queen and an 18-in queen are both 60 × 80 in on top. Depth affects bed height, sheet pocket size and weight, and very deep mattresses with rounded edges can lose a little usable sleeping width at the corners.
Do mattresses get thinner over time?
Foam and fiber compress with use. Many manufacturer warranties count a body impression of about 1 to 1.5 in (2.5 to 4 cm) as a defect, so a loss of depth smaller than that is treated as normal settling.