Prices shown are approximate. Verify current pricing before purchasing.
Mattress sizes are simple in theory, confusing in practice. The same name (king, queen, twin) refers to slightly different dimensions across categories (RV vs home), countries, and even within home mattresses (California king vs Eastern king). Knowing what fits your bedroom, your body, and your bed frame matters more than most shoppers realize.
Standard U.S. mattress sizes
| Size | Width x Length | Best for |
|---|---|---|
| Crib | 28″ x 52″ | Infants, 0-2 years |
| Twin | 38″ x 75″ | Kids, bunk beds, daybeds |
| Twin XL | 38″ x 80″ | College dorms, tall solo sleepers, adjustable bases |
| Full (Double) | 54″ x 75″ | Solo adults, smaller bedrooms, tweens |
| Full XL | 54″ x 80″ | Tall solo sleepers in smaller bedrooms (rare) |
| Queen | 60″ x 80″ | Most popular size. Couples, master bedrooms. |
| King (Eastern King) | 76″ x 80″ | Couples, families with kids/pets |
| California King | 72″ x 84″ | Tall couples, narrow but long bedrooms |
| Split King | 2x (38″ x 80″) | Adjustable beds, couples with different firmness preferences |
How to pick the right size
Solo sleeper
- Under 5’10”: Twin XL or Full
- 5’10” to 6’2″: Full or Queen
- Over 6’2″: Twin XL, Queen, or California King
Couple
- Both partners under 5’10”, small bedroom: Queen (snug)
- Both partners average size, average bedroom: Queen
- Either partner restless or 6’+: King
- Either partner over 6’2″: California King
Bedroom dimensions
- Bedroom under 10×10: Full or Queen
- Bedroom 10×10 to 12×12: Queen or King
- Bedroom over 12×12: Any size
- Long but narrow bedroom: California King
Sizing for two-person bedrooms
Per-partner space at each size:
- Full: 27″ each. Too narrow for two adults.
- Queen: 30″ each. Workable but tight.
- King: 38″ each. Spacious.
- California King: 36″ each, plus 4″ extra length. Better for tall sleepers.
Reference: a standard single bed (twin) is 38″ wide, which is what you each get on a king-size shared bed.
Non-standard sizes
RV / camper
RV mattresses use non-standard dimensions. RV Queen (Short Queen) is 60″ x 75″; RV King is 72″ x 75″ or 72″ x 80″. Always measure before buying.
Bunk beds
Most bunk beds use Twin or Twin XL. Top bunks usually require thinner mattresses (6-8″) for safety rail compliance.
Dog and cat beds
Pet beds vary widely; not standardized to mattress sizes.
Trundle beds
Most trundles use Twin (38″ x 75″). Profile must be under 6″ to fit under the main bed.
How to upgrade size
Going from Full to Queen, Queen to King, or King to California King:
- Measure your bedroom. Bigger mattress means bigger frame and tighter walking clearance.
- Check door clearance. Cal King and King need 36″+ door width to move expanded.
- Buy compressed-in-box if possible. Easier to maneuver into upgraded spaces.
- Plan to replace bedding. Sheets, blankets, comforter all need new size.
- Plan to replace bed frame. Old frame will not fit new mattress.
Sheets and bedding by size
Sheet pocket depth must match mattress thickness. Standard mattresses are 8-12″; thicker premium mattresses (Saatva, Purple Hybrid) are 13-15″. Buy “deep pocket” sheets if your mattress is over 12″ thick.
How to pick today
Solo adult: Queen (most flexibility) or Twin XL (small bedroom).
Couple: Queen (budget) or King (preferred).
Tall couple: California King.
Reminder: Confirm current pricing before purchase.