Mattress Sizes
All mattress sizes below use Western (US) standards and are compatible with standard futon frames, platform beds, tatami mats, and bedding sheets. Use the charts to find the right fit for your space and sleep style.
Standard Mattress Dimensions
| Size | Dimensions (in) | Dimensions (cm) | Best For |
|---|---|---|---|
| Twin | 39" × 75" | 99 × 191 cm | Single sleepers, daybeds, and children's rooms |
| Twin XL | 39" × 80" | 99 × 203 cm | Tall adults, college dorms; place two side by side for a standard King |
| Full | 54" × 75" | 137 × 191 cm | Single adults, studio apartments, convertible futon sofas |
| Queen | 60" × 80" | 152 × 203 cm | Couples, master bedrooms; most popular size overall |
| King | 76" × 80" | 193 × 203 cm | Maximum width for couples; requires a large room |
| California King | 72" × 84" | 183 × 213 cm | Taller sleepers who need extra length over width |
Size Notes
Twin vs. Twin XL: Both are the same width, but the Twin XL adds 5 inches of length — matching the length of a Queen or King. Recommended for anyone over 6 feet tall.
Full: The most popular size for convertible futon sofas. Wide enough for a single adult who wants room to spread out, compact enough for studio living. A Full XL (54" × 80") is also available by custom order for those who need the extra length — see Specialty Sizes below.
Queen: The standard for couples and the most popular mattress size overall. As a bed, it offers the same sleeping surface as a traditional Queen. As a sofa, the extra width creates a deeper seat and taller backrest than most people expect — it works best in larger rooms, and converting it requires more effort than a Full. See our Full vs. Queen guide before deciding.
King vs. California King: A standard King is wider (76"), a California King is longer (84"). Choose King for side-to-side space, California King if legroom is the priority.
Specialty & Non-Standard Sizes
The following sizes are available for select mattresses, protective covers, and accessories. They are not standard futon frame or platform bed sizes.
Extended Lengths
| Size | Dimensions (in) | Dimensions (cm) | Best For |
|---|---|---|---|
| Full XL | 54" × 80" | 137 × 203 cm | Same width as Full with the added length of a Queen. Available by custom order. |
Two-Piece / Split Mattresses
Two-piece mattresses are designed for convertible frames that alternate between sofa and bed configurations. The main section serves as a seat cushion; the ottoman section folds out or moves aside to extend the sleeping surface. They are also easier to carry through tight hallways and staircases.
| Size | Seat Section | Ottoman Section | Total Sleeping Surface |
|---|---|---|---|
| Chair | 28" × 54" | 28" × 21" | 28" × 75" |
| Twin Split | 39" × 54" | 39" × 21" | 39" × 75" |
| Loveseat | 54" × 54" | 54" × 21" | 54" × 75" |
| Queen Split | 60" × 54" | 60" × 26" | 60" × 80" |
Portable & Specialty Beds
| Size | Dimensions (in) | Dimensions (cm) | Best For |
|---|---|---|---|
| Cot | 30" × 75" | 76 × 191 cm | RVs, camping, portable daybeds. Lightweight and easy to store. |
| Crib | 28" × 52" | 71 × 132 cm | Standard baby cribs. Firm and breathable for infants. |
We can also craft futon mattresses, shikibutons, and covers in custom dimensions — for built-in nooks, antique frames, or any non-standard application. Contact us to discuss your requirements.
Japanese Sizing vs. Western Standards
Our futon mattresses, shikibutons, and tatami mats are sold exclusively in Western (US) standard sizes, ensuring compatibility with standard frames and bedding. If you are matching or comparing to traditional Japanese products — such as a Japanese-sized frame or shikibuton purchased abroad — use the table below to find the closest Western equivalent.
| Japanese Size | Dimensions | Western Equivalent(s) |
|---|---|---|
| Single (S) | 100 × 210 cm (39" × 83") |
Twin (99 × 191 cm) or Twin XL (99 × 203 cm) |
| Semi-Double (SD) | 120 × 210 cm (47" × 83") |
Full (137 × 191 cm) |
| Double (D) | 140 × 210 cm (55" × 83") |
Full (137 × 191 cm) or Full XL (137 × 203 cm) |
| Queen (Q) | 160 × 210 cm (63" × 83") |
Queen (152 × 203 cm) |
Standard Western sheets and covers will not fit Japanese-sized mattresses without some overlap or gap.
Thickness Options
| Use Case | Mattress Type | Recommended Thickness |
|---|---|---|
| Floor sleeping (portable) | Shikibuton | 3" – 4" (4" ideal) |
| Floor sleeping (stationary) | Futon mattress | 5" – 6" |
| Tri-fold futon frame | Futon mattress | 4" – 6" (6" ideal) |
| Bi-fold futon frame | Futon mattress | 6" – 8" (8" ideal) |
| Platform bed frame | Futon mattress | 6" – 10" (8" ideal) |
Floor sleeping: Always use a tatami mat or coir pad between the mattress and the floor. Direct floor contact traps moisture and will damage the mattress over time. Shikibutons (3"–4") are designed to be rolled up and stored daily. 3" is very firm and best for those accustomed to traditional floor sleeping; 4" provides better support but is heavier to move. For a stationary floor setup where portability is not a priority, a 5"–6" futon mattress offers better cushioning — flip it monthly.
Tri-fold frames: The mattress must fold into three equal sections, so thickness is the critical constraint. Stay at or below 6". Anything thicker will be too stiff to fold on the frame properly. A 4"–5" mattress works but feels thin for overnight guests; 6" is the recommended balance of comfort and foldability.
Bi-fold frames: The frame folds once, so it tolerates a thicker mattress than a tri-fold. Do not exceed 8" or the frame will not fold. Keep in mind that a Queen-size 8" futon mattress is heavy — if it will regularly be converted by one person, 6" is a more practical choice.
Platform beds and slatted frames: No folding required. Choose thickness based on comfort preference, starting at 6" to ensure you don't feel the slats. 8" is the most popular choice for daily use; 10" is available for those who prefer a deeper sleeping surface.
Natural cotton and wool mattresses compress slightly over time. Rotate and flip your mattress regularly during the first six months for even wear. Note that futon mattresses may measure slightly smaller than the listed dimensions — this is a normal characteristic of how they are produced, and they are designed to fit standard frames correctly.
Frequently Asked Questions
What are standard pillow sizes?
Pillow sizes generally correspond to mattress width. Standard (20" × 26") fits Twin and Full beds; Queen (20" × 30") fits Queen beds; King (20" × 36") fits King and California King beds. Travel/Toddler (12" × 16") is suited for travel or crib use.
How do I choose the right thickness for my frame?
It depends on your frame type. Tri-fold frames: 4"–6" maximum, 6" recommended — thicker mattresses will not fold. Bi-fold frames: 6"–8", 8" recommended — but consider 6" for a Queen if one person is converting. Platform beds: 6"–10", 8" is the most popular choice. For floor sleeping, use a 3"–4" shikibuton (portable) or a 5"–6" futon mattress (stationary). See the Thickness Options section above for full details.
Do your sizes fit standard fitted sheets?
Yes — all sizes use Western standards and work with standard bedding. For shikibutons and futon mattresses under 6" thick, standard deep-pocket sheets may feel loose; our futon covers provide a tailored fit.
What is the benefit of a two-piece / split mattress?
Two-piece mattresses are easier to move through tight spaces and work modularly on convertible frames — the seat section stays in place while the ottoman slides out or acts as a footrest.
Can two Twin XL mattresses make a King?
Yes. Two Twin XL mattresses placed side by side equal a standard King (76" × 80"). This is popular for couples with different firmness preferences or for split-adjustable base setups.
What is the difference between King and California King?
A standard King is wider (76"); a California King is longer (84"). Choose King for more side-to-side space, California King if legroom is your priority or your room is narrower.
Can these mattresses be used for floor sleeping?
Yes, but always place a tatami mat or coir pad underneath — never use a mattress directly on bare floor, as moisture will accumulate and damage it. For portability, a Twin or Full shikibuton (3"–4") is easiest to roll up and store daily. For a stationary floor setup, a 5"–6" futon mattress offers better cushioning — flip it monthly.
Do you offer custom sizes?
Yes. We can craft futon mattresses and shikibutons in custom dimensions for built-in nooks, antique frames, or any non-standard application. Contact us to discuss your requirements.