Bunk Bed Dimensions

A standard twin-over-twin bunk bed is about 42 in wide, 80 in long and 60–70 in tall (107 × 203 × 152–178 cm). The footprint follows the mattresses; the height is set by two clearances: at least 30 in (76 cm) above the lower mattress, so the person below can sit up, and about 33 in (84 cm) between the upper mattress and the ceiling.

Bunk bed sizes

Bunk bedMattressesFootprint, aboutHeight
Twin over twin38 × 75 in (97 × 191 cm)42 × 80 in (107 × 203 cm)60–70 in (152–178 cm)
Twin XL over twin XL38 × 80 in (97 × 203 cm)42 × 85 in (107 × 216 cm)60–70 in
Twin over full38 × 75 over 54 × 75 in57 × 80 in (145 × 203 cm)60–70 in
Full over full54 × 75 in (137 × 191 cm)57 × 80 in (145 × 203 cm)62–72 in (157–183 cm)
Queen over queen60 × 80 in (152 × 203 cm)64–66 × 84–88 in (163–168 × 213–224 cm)65–75 in (165–190 cm)
European single90 × 200 cm96–100 × 206–210 cm155–180 cm

Add the ladder or stairs: a straight ladder needs 12–16 in (30–40 cm) of floor beside the bed, a staircase with storage 18–24 in by 4–5 ft.

Heights and clearances

MeasurementMinimumComfortable
Lower deck (top of the slats)8 in (20 cm)10–16 in (25–40 cm)
Lower mattress to underside of the upper bunk30 in (76 cm)33–36 in (84–91 cm)
Upper deck from the floor54 in (137 cm)56–62 in (142–157 cm)
Upper mattress to ceiling30 in (76 cm)33–36 in (84–91 cm)

Add these up and a bunk bed needs a ceiling of at least 8 ft (244 cm); 9 ft ceilings leave room for a higher lower bunk or thicker mattresses.

Safety rules for the top bunk

  • Guardrails on both sides of the upper bunk, with their top edge at least 5 in (13 cm) above the mattress.
  • A thin mattress on top, 6–8 in (15–20 cm), so the guardrail stays high enough.
  • No gap wider than 3 1/2 in (9 cm) between the rails and the frame, and the opening for the ladder no wider than about 15 in (38 cm).
  • No child under 6 on the upper bunk.
  • Fix the bed to the wall studs, especially when it is built in or very tall.

Building a bunk bed

Build the frame from 18 mm (3/4 in) plywood, never MDF or particle board, and screw every rail and deck support with several screws. Our bunk bed plan uses two solid end panels, a bracing panel between the bunks and guardrails sized from your mattress thickness:

For a single raised bed with a desk underneath, see loft bed dimensions.

Frequently asked questions

What are the dimensions of a twin bunk bed?

About 41–44 in wide, 78–82 in long and 60–70 in tall (104–112 × 198–208 × 152–178 cm), built around two 38 × 75 in mattresses.

What are the dimensions of a queen bunk bed?

About 64–66 in wide and 84–88 in long (163–168 × 213–224 cm), around two 60 × 80 in mattresses, and usually 65–75 in tall. Queen bunks are built for adults.

How much space should be between bunk beds?

At least 30 in (76 cm) between the top of the lower mattress and the underside of the upper bunk, so the person below can sit up.

What ceiling height do you need for a bunk bed?

About 30–36 in (76–91 cm) above the top mattress. With the upper deck at 59 in (1500 mm), that means a ceiling of at least 8 ft (244 cm).

More guides