Full size mattress frame dimensions
A full mattress is 54 × 75 in. The frame around it is larger, and that's the size to measure the room for.
Short answer: a full size mattress is 54 × 75 in.[1 · Oct 29, 2026] One maker's frame chart lists typical full frames at about 56 to 60 in wide and 76 to 80 in long on the outside.2 A frame usually adds about 2 to 5 in on each side.2 Use the listed outside size of the frame you're buying.
Full mattress and frame sizes
| Inches | Centimeters | |
|---|---|---|
| Full mattress | 54 × 75 in[1 · Oct 29, 2026] | 137 × 191 cm |
| Typical full frame, outside | 56–60 × 76–80 in2 | 142–152 × 193–203 cm |
Ranges from one maker's frame size chart.2 At least one maker lists its full mattress at 53 in wide rather than 54,3 so if a full frame or alcove is tight, check the exact model.
Foundation and room
- A platform or slatted frame supports the mattress on its own; a traditional metal frame needs a foundation.3
- One maker's minimum room for a full is 9′ × 10′.3 See twin vs full for kids, queen vs full and the full bed frame size chart.
Questions people ask
What size is a full bed frame?
A full mattress is 54 × 75 in. One maker lists typical full frames at about 56 to 60 in wide and 76 to 80 in long on the outside. A frame usually adds about 2 to 5 in on each side.
Does a full size mattress come with a frame?
Not usually. The mattress and the frame are sold separately. Match the frame to a 54 × 75 in full mattress, then check the listed outside dimensions.
How much space does a full bed need?
One maker lists 9′ × 10′ as the minimum room for a full. A frame can add up to 5 in each way, so measure the outside of the frame, not just the mattress.
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Sources: 1. Sleep Foundation, Mattress sizes and dimensions guide. 2. 
Casper, Bed frame size chart and dimensions guide. 3. Casper, Queen size bed dimensions: size, room fit, and how it compares. Checked Oct 29, 2026. Trademarks belong to their owners; figures are restated in our own words and tables, not reproduced.