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Full size mattress dimensions

A full is 54 × 75 in. Here's what that means in cm and feet, who it fits, and the room it needs.

Short answer: a full size mattress is 54 × 75 in (137 × 191 cm), or 4′ 6″ × 6′ 3″.^{[1 · Oct 29, 2026]} It suits a single adult under 6 ft; a couple can share one only in a pinch.^{[1 · Oct 29, 2026]} One maker's minimum room is 9′ × 10′.²

Full size mattress dimensions

Width and length are standardized; thickness is not, so it varies by model.^{[1 · Oct 29, 2026]} At least one maker lists its full at 53 in wide rather than 54.² If a frame or alcove is tight, check the exact model's listed size. We converted to centimeters at 2.54 cm per inch^{[3 · Oct 29, 2026]} and rounded to the nearest cm.

Who a full size mattress suits

• A single adult under 6 ft who wants more room than a twin.^{[1 · Oct 29, 2026]}
• A guest room, or a growing child in a room that can take the extra 16 in of width versus a twin.^{[1 · Oct 29, 2026]}
• A couple only in a pinch: 27 in each is tight compared with a queen's 30 in (our arithmetic).^{[1 · Oct 29, 2026]}

Compare a full with a queen on our queen vs full page, or with a twin on twin vs full for kids.

Room size for a full

One maker lists 9′ × 10′ as the minimum room for a full, compared with 10′ × 10′ for a queen.² A frame can add up to 5 in each way,² so measure the outside of the frame, not just the mattress. Typical full frames are about 56 to 60 × 76 to 80 in on the outside; see full bed frame size. For a small bedroom, also see best mattress for a small bedroom.

Sources: 1. Sleep Foundation, Mattress sizes and dimensions guide. 2. Casper, Queen size bed dimensions: size, room fit, and how it compares. 3. NIST, SI units: length. Checked Oct 29, 2026. Trademarks belong to their owners; figures are restated in our own words and tables, not reproduced.