Bed and mattress sizes
Every standard mattress size in the US (Twin to Cal-King), plus international variants (European, UK, Asian). Dimensions, frame footprints, bedroom sizing requirements, and the history of how these standards evolved.
US mattress sizes cluster into six standards: Twin, Twin XL, Full, Queen, King, California King. These standards have been remarkably stable since the 1940s and 1950s, when major mattress manufacturers (Sealy, Serta, Simmons) standardized the categories. The dimensions don't quite make geometric sense — they're inherited from cotton ticking sizes and 19th-century iron bedframe standards — but they're now the universal language of American bedroom design.
International mattress sizes differ from US — sometimes significantly. European (continental) sizes use centimeters and slightly different proportions. UK sizes are similar to European but with traditional names. Asian markets have their own standards. Modern American manufacturers often offer European sizes for customers who travel internationally or have international family bedding.
This page is the comprehensive reference for bed and mattress sizes. For nightstand and dresser dimensions, see nightstand and dresser dimensions. For bedroom layout, see master bedroom layout guide.
In this guide
- 1
US standard mattress sizes
Twin. - Dimensions: 38 × 75 inches (97 × 191 cm). - Frame typically: 40–42 × 78–80 inches. - Used by: 1 person; children; guest beds; college dorms. - Original purpose: single-person beds in early 20th century American homes. Twin XL (Twin Extra Long). - Dimensions: 38 × 80 inches (97 × 203 cm). - Frame typically: 40–42 × 84 inches. - Used by: tall single users; college dorms (where length matters more than width); convertible beds. - Difference from Twin: same width, 5 inches longer. Full (also called Double). - Dimensions: 54 × 75 inches (137 × 191 cm). - Frame typically: 56–58 × 78–80 inches. - Used by: 1 person who wants extra space; 2 small people (tight); kid beds (10+ years). - Common in: smaller bedrooms (10×10 to 11×12); guest bedrooms. Queen. - Dimensions: 60 × 80 inches (152 × 203 cm). - Frame typically: 64–66 × 84–86 inches. - Used by: 2 adults (comfortable); 1 adult who wants extra space. - Most common US adult bed. Standard for master bedrooms in mid-range housing. - Fits in: 10×12 to 12×14 master bedrooms. King (also called Eastern King). - Dimensions: 76 × 80 inches (193 × 203 cm). - Frame typically: 80–82 × 84–86 inches. - Used by: 2 adults with extra space; family with co-sleeping kids. - Common in: larger master bedrooms (12×13 to 14×14+). California King (Cal-King, Western King). - Dimensions: 72 × 84 inches (183 × 213 cm). - Frame typically: 76 × 88 inches. - Used by: tall sleepers (the 84-inch length). - Difference from King: 4 inches narrower, 4 inches longer. - Common in: California and Western US homes; tall sleeper households. Total US standard sizes: 6 standard sizes covering virtually all American bedroom needs. Manufacturers sometimes offer 'Split Queen' (two narrow halves) and 'Split King' (two Twin XL beds together) for adjustable bed frames where each side moves independently.
- 2
European mattress sizes
Continental European standards (used in EU countries other than UK): Single (90×190). - Dimensions: 90 × 190 cm (35 × 75 inches). - US equivalent: close to Twin (38 × 75). Single XL (90×200). - Dimensions: 90 × 200 cm (35 × 79 inches). - US equivalent: close to Twin XL (38 × 80). Double / Continental Double (140×200). - Dimensions: 140 × 200 cm (55 × 79 inches). - US equivalent: close to Full (54 × 75) but longer. Queen / European Queen (160×200). - Dimensions: 160 × 200 cm (63 × 79 inches). - US equivalent: close to Queen (60 × 80) but slightly wider. King / European King (180×200). - Dimensions: 180 × 200 cm (71 × 79 inches). - US equivalent: between Queen and King. Super King (200×200). - Dimensions: 200 × 200 cm (79 × 79 inches). - Larger than US King; common in Scandinavian and luxury European bedrooms. Key difference: European sizes are generally longer (200 cm = 79 inches) than US (75 or 80 inches). European widths cover a wider range than US standards.
- 3
UK mattress sizes
UK standards (sometimes confusingly different from continental Europe): Single (3'). - Dimensions: 90 × 190 cm (3' × 6'3" / 35 × 75 inches). - Equivalent to continental Single. Small Double (4'). - Dimensions: 120 × 190 cm (4' × 6'3" / 47 × 75 inches). - Smaller than continental Double; used in compact UK bedrooms. Double (4'6"). - Dimensions: 135 × 190 cm (4'6" × 6'3" / 53 × 75 inches). - Close to US Full. King Size (5'). - Dimensions: 150 × 200 cm (5' × 6'6" / 59 × 79 inches). - Close to US Queen. Super King (6'). - Dimensions: 180 × 200 cm (6' × 6'6" / 71 × 79 inches). - Close to continental King. Emperor (7'). - Dimensions: 215 × 215 cm (7' × 7' / 85 × 85 inches). - Larger than any US standard size; rare in residential. Caesar (8'). - Dimensions: 240 × 220 cm (8' × 7'3" / 95 × 87 inches). - Very large; novelty / luxury. Note: UK 'King' is smaller than US 'King'. UK 'Super King' is closer to US King.
- 4
Asian and other international sizes
Japanese sizes (used in Japan, sometimes Korea): Single (97×195). - Dimensions: 97 × 195 cm (38 × 77 inches). - Close to US Twin. Semi-Double (122×195). - Dimensions: 122 × 195 cm (48 × 77 inches). - Between US Twin and Full. Double (140×195). - Dimensions: 140 × 195 cm (55 × 77 inches). - Close to US Full. Queen (160×195). - Dimensions: 160 × 195 cm (63 × 77 inches). - Close to US Queen but shorter. King (180×195). - Dimensions: 180 × 195 cm (71 × 77 inches). - Close to US Queen+/King but shorter. Japanese mattresses are generally shorter than US (195 cm = 77 inches vs US 80 inches) reflecting average Japanese height. Australian sizes: Single (92×188). - Dimensions: 92 × 188 cm (36 × 74 inches). - Close to US Twin (slightly smaller). King Single (107×203). - Dimensions: 107 × 203 cm (42 × 80 inches). - Wider than Twin XL. Double (138×188). - Dimensions: 138 × 188 cm (54 × 74 inches). - Close to US Full but shorter. Queen (153×203). - Dimensions: 153 × 203 cm (60 × 80 inches). - Exactly US Queen. King (183×203). - Dimensions: 183 × 203 cm (72 × 80 inches). - Smaller than US King; close to King between US standards.
- 5
Frame footprints — what to add for the bed frame
The mattress is one dimension; the bed frame (which holds the mattress, plus headboard, footboard, side rails) is larger. Standard frame additions (per side): - Width: add 2–4 inches per side (4–8 inches total) for side rails. - Length: add 2–4 inches at headboard, 0–4 inches at footboard. Frame footprints for common mattresses: Twin (38×75 mattress): - Frame: 40–42 × 78–80 inches typical. - Headboard adds 4–6 inches of total height above mattress. Full (54×75): - Frame: 56–58 × 78–80 inches. Queen (60×80): - Frame: 64–66 × 84–86 inches. - The most common frame footprint to plan for. King (76×80): - Frame: 80–82 × 84–86 inches. - Substantial; reserve significant bedroom floor area. Cal-King (72×84): - Frame: 76 × 88 inches. Bed-frame heights: - Platform bed (mattress directly on frame): 14–18 inches above floor. - Standard bed frame (box spring + mattress on rails): 18–22 inches. - Higher 'sleigh' or 'four-poster' frames: 20–28 inches. - Headboard typically: 36–60 inches above mattress.
- 6
Bedroom sizing — minimum and comfortable
Bedroom dimensions are driven by the bed plus walkway requirements around it. Walkway requirements: - Each side of bed: 30 inches minimum; 36 inches comfortable. - Foot of bed to dresser or wall: 36 inches minimum. - Foot of bed with bench: 48 inches (bench depth + walkway). Minimum bedroom size for each bed: - Twin: 8×9 feet. Fits a Twin bed on one wall + 30-inch walkway on the open side + small dresser opposite. - Twin XL: 8×10 feet. Same as Twin but 5 inches longer. - Full: 9×10 feet. Full bed centered with 30-inch walkways each side. - Queen: 10×12 feet minimum. Queen bed centered with 30-inch walkways each side + dresser opposite at 36 inches. - King: 12×13 feet minimum. King bed centered with 30-inch walkways each side + dresser opposite at 36 inches. - Cal-King: 12×14 feet minimum. Same as King but 4 inches longer. Comfortable bedroom size (each): - Twin: 10×10 feet. - Queen: 11×13 feet. - King: 13×14 feet. - Cal-King: 13×15 feet. Generous bedroom (with sitting area, bench at foot, walkway to bathroom): - Queen: 12×14 feet. - King: 14×16+ feet. - Cal-King: 14×16+ feet.
- 7
History of mattress size standardization
Pre-1900. American mattresses were custom-sized to iron bedframes that varied widely by manufacturer. 'Three-quarter beds' (intermediate between Twin and Full) were common; sizes weren't standardized. 1900-1940. Spring mattress technology spread; cotton ticking sizes drove dimensional standardization. The 'Single' (later 'Twin') at ~38 inches wide and the 'Double' (later 'Full') at ~54 inches wide became dominant by 1930. 1940s-1950s. Major mattress manufacturers (Sealy, Serta, Simmons) standardized the modern category structure. 'Queen' (60×80) was introduced in 1958; 'King' (76×80) in 1960. The size categories used today are essentially unchanged since this period. 1960s. California-King introduced as a longer (but narrower) alternative for tall sleepers. Different historical origin from Eastern King. 1980s. Twin XL became standard for college dorms (5-inch longer Twin) due to taller average American student heights. 2010s-present. Adjustable bed frames (where each side of the mattress moves independently for sleep angle adjustment) introduced 'Split Queen' and 'Split King' configurations. Cal-King and King remain the largest standard sizes for couples wanting maximum sleeping space.
- 8
Choosing the right size — by use case
For 1 adult: - Solo: Twin XL or Full minimum. Queen comfortable. - With dogs/cats: Queen minimum. - Tall (6'+): Twin XL or Cal-King for length. For 2 adults: - Tight: Full (compromised but works). - Standard: Queen. - Comfortable: King. - Co-sleeping kids: King (the extra width is valuable). For kids: - Toddler (2-5): Twin or Full. - School-age (5-12): Twin or Full. - Tween/teen: Twin XL or Full. For guest bedrooms: - Solo guest: Full minimum. - Couple: Queen minimum. For small bedrooms (under 10×10): - Full is the maximum that fits. - Queen requires 10×12 minimum. For master bedrooms: - Standard: Queen (most US master bedrooms). - Generous: King. - Luxury / tall sleepers: Cal-King.
- 9
In Room Sketch 3D
Room Sketch 3D's catalog includes: - All 6 US standard sizes (Twin, Twin XL, Full, Queen, King, Cal-King). - European Queen, King, Super King. - UK Single, Double, King, Super King. - Various bed frame styles (platform, four-poster, sleigh, mid-century, contemporary). To place a bed: 1. Furnish Panel → Bedroom tab → Beds category. 2. Filter by size if needed. 3. Click to preview, click to place. Standard bed orientation: - Headboard against an interior wall (not under a window; not in line with the bedroom door). - Width (long dimension) parallel to the headboard wall. - Walkways on three sides (or two sides for beds against a wall). Smart Flow Check enforces: - 30-inch minimum walkway on accessible sides. - 36-inch minimum foot-of-bed clearance. - Door swing arcs don't conflict with bed.
Tips
Queen is the universal default for adult couples
60×80 inches. Fits most US master bedrooms. Provides adequate sleeping space for two adults. The standard recommendation unless the room is large enough for King.
Cal-King for tall sleepers, King for couples wanting space
Cal-King is 4 inches longer than King; King is 4 inches wider. Pick based on whether length or width is the priority.
Twin XL for college students and tall single adults
Same width as Twin (38 inches) but 5 inches longer (80 vs 75). Critical for tall sleepers; standard for many college dorms.
Add 4-8 inches to mattress width for frame footprint
Don't plan for the bedroom based on mattress dimensions alone — the frame is larger. A Queen mattress is 60×80 but the frame is 64×84 typically.
Common confusions
King bed in a 10×11 bedroom
King needs 12×13 minimum. In a 10×11 room, the King dominates with no walkway space. Use Queen instead.
Buying European/UK mattress for US frame
Sizes don't match. A UK King (150×200 cm) doesn't fit a US Queen or King frame. Match the mattress to the frame standard.
Twin in a 12×12 master bedroom
Twin in a master is undersized — the bedroom looks too big for the bed. Match bed scale to room scale.
Frequently asked questions
What's the size of a Queen mattress?
60 × 80 inches (152 × 203 cm). Frame typically 64–66 × 84–86 inches. The most common US adult bed size.
What's the difference between King and California King?
King: 76 × 80 inches (wider). California King: 72 × 84 inches (longer, narrower). Cal-King fits taller sleepers; King fits couples wanting more side-to-side space.
How big a room do I need for a King bed?
12 × 13 feet minimum. That's the King bed (76×80 mattress, 80×84 frame) plus 30-inch walkways on three sides plus 36 inches at the foot. Comfortable: 13×14+ feet.
Is a Queen large enough for two adults?
Yes — Queen is the standard US adult couple bed. 60 inches wide means each person has 30 inches of personal space. Comfortable for most couples; tight if both partners are large or if pets share the bed.
What's the difference between Twin and Twin XL?
Same width (38 inches), 5 inches longer (Twin: 75 inches; Twin XL: 80 inches). Twin XL accommodates taller sleepers; standard for college dorms and convertible beds.
Are US and European mattress sizes the same?
No — they differ by several inches in length and have different width standards. US Queen: 60×80 inches. European Queen: 63×79 inches. Don't buy a European mattress assuming it'll fit a US frame.
What's a Split King?
Two Twin XL mattresses (38×80 each) used together to form the dimensions of a standard King (76×80). Common on adjustable bed frames where each side moves independently for sleep angle adjustment.
Start designing your room
Draw it, furnish it, walk through it in 3D — on web, iOS, and Android.
Open Room Sketch 3DOne-time purchase · No subscription · Web, iOS & Android