Dimensions / Furniture / Bed frames / Platform bed
A platform bed is a frame with its own slatted or solid base, so it needs no box spring. With a mattress it stands about 46 cm (18 in) tall, against 64 cm (25 in) for a standard bed; Thuma’s queen Classic is 165 × 216 cm (65 × 85 in) outside and 33 cm (13 in) to the top of its rails. Mattress makers want the slats no more than 8.9–10 cm (3.5–4 in) apart.
| With a mattress | Low frames, to the mattress top | Slat gap, Purple |
|---|---|---|
| 46cm18 in | 30–40cm | 8.9cm3.5 in |
Sources: Amerisleep, Dreams, Purple (warranty). Checked October 2026.
Enter the frame, your knee height and what should go under the bed. Each check uses the numbers in the tables on this page.
All in centimetres. 1 in = 2.54 cm.
To bring the bed to your 52 cm knee height you need a 21 cm mattress, within the usual 20–36 cm.
Measure from the floor to the middle of your kneecap, and the base at the top of the slats.
The slats are 7 cm apart, within the 8.9 cm limit.
Purple’s limit; Tempur-Pedic and Saatva allow up to 10 cm. Queen and larger frames also need a center support.
It is 18 cm tall and there is 23 cm under the frame, 5 cm to spare.
Take the frame’s height under furniture from its spec sheet.
Choosing a low bed for a small room? Photograph it, mark the walls and the floor in SizeMarker and check the frame before you order.
Mark a photo| Measurement | Height |
|---|---|
| Platform bed with a mattressAmerisleep, Nectar | 46 cm18 in |
| Standard bed with a mattress | 64 cm25 in |
| Platform and low-profile frames, floor to mattress topDreams, UK | 30–40 cm |
| Standard beds and divans, floor to mattress top | 45–55 cm |
| Knee-level frameSleep Foundation | 30–41 cm12–16 in |
| Mattress thicknessCasper | 20–36 cm8–14 in |
| Thuma Classic, to the top of the rails | 33 cm13 in |
| Thuma Classic, to the slats | 31 cm12 1/4 in |
Sources: Amerisleep · Nectar · Dreams · Sleep Foundation · Casper · Thuma
On a slatted frame used with no box spring or foundation.
| Rule | Size |
|---|---|
| Purple: largest slat gap | 8.9 cm3.5 in |
| Tempur-Pedic: largest slat gap | 10 cm4 in |
| Tempur-Pedic: narrowest slat | 7.6 cm3 in |
| Saatva: slat gap | Under 10 cmunder 4 in |
| UK mattress makers: largest gapDunlopillo and Relyon the least, Tempur the most | 6–9 cm |
| Purple’s own platform slats, apart | 5–7 cm2–2.75 in |
| Center support and legsQueen, King and California King; Twin and Full need 4 legs | 5–6 legs |
Sources: Purple (warranty) · Tempur-Pedic · Saatva · MattressOnline · Purple
| Frame | Width × length | Under the frame | Max load |
|---|---|---|---|
| IKEA MALM, QueenAdjustable sides for thicker mattresses; midbeam included | 168 × 211 cm66 1/8 × 83 1/8 in | 21 cm8 1/4 in | — |
| IKEA NEIDEN, Full | 139 × 195 cm54 3/4 × 76 3/4 in | 20 cm7 7/8 in | — |
| Thuma Classic, QueenSlats just under 3 in apart | 165 × 216 cm65 × 85 in | 23 cm9 in | 454 kg1,000 lb, with the mattress |
Sources: IKEA (MALM) · IKEA (NEIDEN) · Thuma
A little bigger than its mattress. Thuma’s queen Classic is 165 × 216 cm (65 × 85 in) and IKEA’s queen MALM 168 × 211 cm (66 1/8 × 83 1/8 in); with a mattress a platform bed stands about 46 cm (18 in) tall.
No. A platform frame has its own slatted, solid wood or metal platform, which Sleep Foundation notes removes the need for a separate foundation; Thuma even advises against adding one to its bed.
Purple’s warranty allows at most 8.9 cm (3.5 in) between slats; Tempur-Pedic allows 10 cm (4 in) with slats at least 7.6 cm (3 in) wide, and UK mattress makers 6–9 cm. Check your own mattress warranty before you buy the frame.
Yes. Purple and Tempur-Pedic ask for a center support and 5–6 legs on Queen, King and California King frames, and IKEA includes its SKORVA midbeam with the MALM because the frame needs it for stability.
Low: about 46 cm (18 in) with a mattress, against 64 cm (25 in) for a standard bed (Amerisleep). Dreams puts platform and low-profile frames at 30–40 cm to the mattress top, against 45–55 cm for standard beds.
On the frames here, 20 cm (7 7/8 in) under IKEA’s NEIDEN, 21 cm (8 1/4 in) under the MALM and 23 cm (9 in) under Thuma’s Classic. Check a storage box or robot vacuum against it with the tool above.
Platform frames are bought by mattress size and height, and buyers ask about the slat gap and the center support because mattress warranties depend on them. Mark the real width, length and height on your own product photo in SizeMarker, as in the picture at the top, and send one product card for WhatsApp or WeChat.
