Short answer. A twin is 38 × 75 in (96.5 × 190.5 cm), a full is 54 × 75 in (137.2 × 190.5 cm), a queen is 60 × 80 in (152.4 × 203.2 cm) and a king is 76 × 80 in (193 × 203.2 cm). The queen is the most common mattress size in the US. Twin and full beds are 75 in long; twin XL, queen and king are 80 in, and a California king is 84 in. These are mattress sizes: the frame and headboard add more. Leave about 24 to 31 in (60 to 80 cm) beside the bed on each side you get in from, and 20 to 28 in (50 to 70 cm) at the foot.
US mattress sizes chart
| Bed | Size in cm | Size in inches | Good to know |
|---|---|---|---|
| Twin | 96.5 × 190.5 | 38 × 75 in | The smallest standard size; also called a single |
| Twin XL | 96.5 × 203.2 | 38 × 80 in | A twin 5 in longer, for tall sleepers |
| Full | 137.2 × 190.5 | 54 × 75 in | Also called a double |
| Queen | 152.4 × 203.2 | 60 × 80 in | The most common size in the US |
| King | 193 × 203.2 | 76 × 80 in | The widest standard size; two twin XLs side by side |
| California king | 182.9 × 213.4 | 72 × 84 in | 4 in narrower than a king, 4 in longer |
Brands do not all agree to the half inch. The industry standard sizes are half an inch smaller than the round numbers (a queen 60 × 79.5 in, a king 76 × 79.5 in), so a mattress and a frame from different brands can differ slightly. Check the inches on the label.
Full vs queen vs king: how much bed each of you gets
- Full: 27 in (68.6 cm) each, about the width of a crib mattress (27 1/2 in at IKEA).
- Queen: 30 in (76.2 cm) each.
- California king: 36 in (91.4 cm) each.
- King: 38 in (96.5 cm) each, a whole twin per person.
Going from a full to a queen gives you 6 in more width and 5 in more length. From a queen to a king you gain 16 in of width and no length.
The room each bed needs
The bed and its walkways alone, with the head against a wall. From a full up, the bed has a walkway on both sides; a twin goes against a side wall with one walkway. "Snug" is 60 cm (about 2 ft) beside the bed and 50 cm (about 20 in) at the foot; "comfortable" is 80 cm (about 31 in) and 70 cm (about 28 in).
| Bed | Snug | Comfortable |
|---|---|---|
| Twin | 5 ft 2 in × 7 ft 11 in (1.57 × 2.41 m) | 5 ft 9 in × 8 ft 7 in (1.77 × 2.61 m) |
| Twin XL | 5 ft 2 in × 8 ft 4 in (1.57 × 2.53 m) | 5 ft 9 in × 9 ft (1.77 × 2.73 m) |
| Full | 8 ft 5 in × 7 ft 11 in (2.57 × 2.41 m) | 9 ft 9 in × 8 ft 7 in (2.97 × 2.61 m) |
| Queen | 8 ft 11 in × 8 ft 4 in (2.72 × 2.53 m) | 10 ft 3 in × 9 ft (3.12 × 2.73 m) |
| King | 10 ft 3 in × 8 ft 4 in (3.13 × 2.53 m) | 11 ft 7 in × 9 ft (3.53 × 2.73 m) |
| California king | 9 ft 11 in × 8 ft 8 in (3.03 × 2.63 m) | 11 ft 3 in × 9 ft 4 in (3.43 × 2.83 m) |
A dresser needs its own depth plus room to pull out the drawers, and the bedroom door needs room to swing. A room that just fits the bed on paper is often a squeeze in real life.
Full vs double, king vs California king and other mix-ups
- A full and a double are the same bed. 54 × 75 in, sold under both names.
- A California king is not a bigger king. It is 4 in narrower (72 against 76 in) and 4 in longer (84 against 80 in). King sheets and frames do not fit it.
- Two twin XLs make a king. 38 + 38 = 76 in wide, 80 in long. Two plain twins are 5 in too short.
- Twin and full beds are short for tall sleepers. At 75 in they are 5 in shorter than a twin XL or a queen; one retailer advises 80 in or more for anyone over 6 ft.
- European and UK sizes do not match US frames. A European 160 × 200 cm bed is 3 in (7.6 cm) wider than a queen and about 1 1/4 in (3.2 cm) shorter; a UK king (150 × 200 cm) is a little smaller than a US queen. Buy a mattress in the size the frame was made for.
- IKEA US sells US sizes. Its mattress page lists twin, full, queen and king, measured in inches.
How to measure
- The mattress, not the frame. US sizes are mattress sizes. Measure the old mattress's width and length if you are replacing one.
- The frame's inside, if the frame stays: from rail to rail and from headboard to footboard.
- The room, wall to wall at floor level, and where the window, the closet door and the bedroom door sit.
- The way in. A king box spring may come in two halves; a king or California king mattress has to bend around the stairs. See our guide "Will it fit through the door?".
Common mistakes
- Buying by the name. "Double", "queen" and "king" mean different sizes in the US, the UK and Europe. Buy by the inches.
- Forgetting the frame. A headboard, a footboard and a chunky frame can add several inches to the length.
- Measuring the room empty. The dresser drawers, the nightstands and the door swing all take the space the bed seemed to have.
See the bed in your own room
In Flatwalk you draw or photograph your home's floor plan and walk through it in 3D. Beds from real stores stand at their true size, so you can see whether a king leaves room for the closet door, and the tape measure reads any gap in feet and inches or in centimeters.
What it does not do: Flatwalk does not choose a bed for you, and your plan is only as accurate as the measurements you give it. Measure the real room with a tape measure.
Also for the US: door widths.
What Flatwalk does that older planners skip
Lights
Add ceiling lights, lamps and LED strips and see each room in the evening, not only by day.
Your home in its city
Enter your address and the street and buildings around you appear in 3D, wherever the map has them.
Sun for your address
See where the sun falls on any date and at any hour, before a new piece spends all summer in it.
One piece, in your own room
Through the live camera or in a photo of the room, stand it on your own floor at its true size before you buy.
Detail
Doors, radiators, kitchens, closets and bathrooms built piece by piece, so new furniture sits against what is really there.
Made for a thumb
Tap a piece and its choices appear: move it, turn it, swap it for another.
Swipe for more. Every picture is the app itself.
One home, free
Most people plan one home. For that, Flatwalk costs nothing: no time-limited trial and no card needed. Drawing your home, furniture at its true size, the tape measure, lights, sun and walking are all part of it, and each AI tool comes with one free try. A membership is for people who want more homes or more AI.
Questions people ask
What are the dimensions of a king size bed? A US king is 76 × 80 in (193 × 203.2 cm). A California king is 72 × 84 in: narrower, but longer.
What are the dimensions of a queen size bed? 60 × 80 in (152.4 × 203.2 cm). It is the most common mattress size in the US.
What are the dimensions of a full size bed? 54 × 75 in (137.2 × 190.5 cm). A full is the same bed as a double.
Full vs queen: what is the difference? A queen is 6 in wider and 5 in longer than a full. Shared, a full gives each person 27 in and a queen 30 in.
What size room do you need for a queen bed? For the bed and walkways alone, about 8 ft 11 in × 8 ft 4 in (2.72 × 2.53 m), with 2 ft on each side and 20 in at the foot. A king needs about 10 ft 3 in × 8 ft 4 in. A dresser and the door swing need more space on top of that.
Flatwalk lets you place real beds at their true size in a 3D plan of your own home, free for one home. It is coming soon to Google Play; join the waiting list at flatwalk.app.
Join the waiting list