Loft Bed Dimensions
A twin loft bed is about 41–43 in wide and 78–80 in long (105 × 200 cm), built around a 38 × 75 in mattress, with the deck 30–72 in (76–183 cm) off the floor. The height decides what fits underneath, a desk, a sofa or storage, and the ceiling decides how high you can go: you need about 33 in of air above the mattress to sit up.
Loft bed sizes
| Mattress | Mattress size | Frame, about |
|---|---|---|
| Twin | 38 × 75 in (97 × 191 cm) | 41–43 × 78–80 in |
| Twin XL (dorms) | 38 × 80 in (97 × 203 cm) | 41–43 × 83–85 in |
| Full | 54 × 75 in (137 × 191 cm) | 57–59 × 78–80 in |
| European single | 90 × 200 cm | 95–100 × 205 cm |
Add the ladder: a straight ladder at the end or side takes 12–16 in (30–40 cm) of floor, an angled one more. Stairs with storage need about 18–24 in by 4–5 ft.
How high to build it
| Loft | Deck height | What fits underneath |
|---|---|---|
| Low loft | 30–45 in (76–114 cm) | Drawers, toy storage, a play space |
| Mid loft | 45–55 in (114–140 cm) | A small desk for a child, a reading nook |
| High loft | 55–72 in (140–183 cm) | A desk for an adult, a sofa, a wardrobe |
To sit at a desk under the loft, an adult needs about 50–55 in (127–140 cm) of clear height under the deck; a child needs less.
Ceiling height
Add the deck height, the mattress and the space to sit up:
ceiling ≥ deck height + mattress thickness + 33 in (84 cm)
| Ceiling | Highest comfortable deck (with a 6 in mattress) |
|---|---|
| 8 ft (96 in, 244 cm) | about 57 in (145 cm) |
| 9 ft (108 in, 274 cm) | about 69 in (175 cm) |
| 10 ft (120 in, 305 cm) | about 72 in, the usual maximum |
Guardrails and safety
- Guardrails on all four sides, the top at least 5 in (13 cm) above the mattress surface, so use a thin mattress (6–8 in) on a loft.
- Gaps in the guardrail and between the rail and the frame no wider than 3 1/2 in (9 cm), so a child's head cannot get stuck.
- Ladder rungs about 10–12 in (25–30 cm) apart, fixed so they cannot turn.
- Children under 6 should not sleep on a raised bed.
- Fix the bed to the wall studs, especially a high loft: a loaded bed with someone climbing the ladder pushes hard sideways.
Building a loft bed
Build the posts and rails strong enough for an adult: the deck should carry at least 400 lb (180 kg) without moving. Our loft bed plan sizes the frame, guardrails and ladder from the mattress and the deck height you type:
For a bed at floor level, see bed frame dimensions.
Frequently asked questions
What are the dimensions of a twin loft bed?
A twin mattress is 38 × 75 in (97 × 191 cm), so a twin loft bed frame is about 41–43 in wide and 78–80 in long, plus the ladder if it sits at the side.
How high is a loft bed?
Low lofts put the mattress deck at 30–45 in (76–114 cm), mid lofts at 45–55 in, and high lofts, with room for a desk underneath, at 55–72 in (140–183 cm).
What ceiling height do you need for a loft bed?
Enough to sit up in bed: about 30–36 in (76–91 cm) between the top of the mattress and the ceiling. Under an 8 ft ceiling, keep the deck at about 54–58 in.
How high should loft bed guardrails be?
The top of the guardrail should be at least 5 in (13 cm) above the top of the mattress, on all four sides, with gaps no wider than 3 1/2 in (9 cm).