Mattress sizes, made simple
Find the mattress size that fits your life
Twin to California king in inches and centimeters, plus a quick finder that weighs who sleeps in the bed, how tall you are and how big your room is. Every figure links to its source.
Find my sizeSee the size chart
- Inches and cm
- Sources on every figure
- No sign-up

Which size do I need?
Answer four quick questions. Results update as you go.
A starting point based on published sizing advice, not a guarantee. "Tight" means less than 24 in of walkway but at least 12 in (our cut-off). Leave the room size blank to skip the room check.
At a glance
Standard mattress sizes
Drawn to scale.
| Size | Inches | Centimeters | Best for |
|---|---|---|---|
| Twin | 38 × 75 in | 97 × 191 cm | Kids, teens and single adults under 6 ft. |
| Twin XL | 38 × 80 in | 97 × 203 cm | Teens and single adults over 6 ft. |
| Full | 54 × 75 in | 137 × 191 cm | Single adults under 6 ft; a couple only in a pinch. |
| Queen | 60 × 80 in | 152 × 203 cm | Couples without kids or pets in the bed. |
| King | 76 × 80 in | 193 × 203 cm | Couples who want the most width, or share with a child. |
| California king | 72 × 84 in | 183 × 213 cm | Taller couples, or couples sharing with a pet. |
Sizes and who they suit from a sleep-research site's size guide.[1 · Oct 29, 2026] Thickness isn't standard and varies by model.[1 · Oct 29, 2026] Full chart with split king, Olympic queen and cm
Room to breathe
How much space to leave around a bed

Side by side
Queen, king or something in between?
- Queen vs full: a queen is 6 in wider and 5 in longer.[1 · Oct 29, 2026]
- King vs California king: 4 in wider vs 4 in longer.[1 · Oct 29, 2026]
- Twin vs twin XL: same width, 5 in more length.[1 · Oct 29, 2026]



Bedding
Sheets that stay on
Match the sheet size to the mattress, then the pocket depth to its thickness. Standard pockets fit about 7 to 14 in; extra-deep pockets fit 16 to 24 in.[4 · Oct 29, 2026]
Guides
Everything about mattress sizes
- Mattress size chart: inches, cm and feet
- Which size mattress do I need?
- Room size for a queen or king bed: clearances
- Sheet sizes and pocket depth by mattress size
- Bed frame sizes: outside dimensions chart
- Queen vs full: size difference
- King vs California king: size difference
- Twin vs twin XL: size difference
- Mattress in a box buying guide
- Delivery: doorways, stairs and tight turns
- RV, oversized and crib mattress sizes
Affiliate links: if you buy through a link in this box we may earn a commission, at no extra cost to you. It does not change the sizes or sources on this page. How we handle affiliate links.
Sources: 1. Sleep Foundation, Mattress sizes and dimensions guide. 2. Casper, Queen size bed dimensions: size, room fit, and how it compares. 3. Casper, How do Casper mattresses ship?. 4. Sleep Foundation, Bed sheet sizes. Checked Oct 29, 2026. Trademarks belong to their owners; figures are restated in our own words and tables, not reproduced.