King Bed Dimensions: Complete U.S. Guide to King Mattresses

A king bed measures 76 inches wide by 80 inches long (193 cm x 203 cm) and is the widest standard mattress size in the United States. Each sleeper on a king gets approximately 38 inches of personal width—the equivalent of a twin bed each. It is the size for couples who want maximum space, families who co-sleep with children or pets, and anyone furnishing a larger primary bedroom.

A king is sometimes called an "Eastern king" to distinguish it from the California king, which trades width for length.

Pro Tip: A king and a queen are the same length (80 inches). The 16 extra inches are all width—exactly what co-sleeping families and restless sleepers need.

We recommend a minimum room size of 12 x 10 feet for a king bed, with 12 x 12 feet or larger for a comfortable layout with nightstands, a dresser, and clear walkways on all sides. In smaller rooms, a king dominates the floor plan; measure the room and account for existing furniture before ordering.

One more measurement matters at this size: doorways, hallways, and stairwells. A one-piece king is the hardest mattress to maneuver into a home. If your route includes a narrow staircase or tight corners, a split king—two Twin XL mattresses—delivers the same footprint in two manageable pieces.

To check your own room, the math is simple: measure the room's width in inches, subtract the mattress width, and see what's left for walkways and furniture. Keep at least 24 inches of walkway on each open side of the bed, and remember that dressers need roughly 36 inches of clearance in front to open drawers. A worked example: a King (76" wide) in a 12-foot-wide room (144") leaves 34 inches per side — comfortable. In a 10-foot room (120"), it leaves just 22 inches per side, below the walkway guideline — which is exactly why we recommend 12 feet of width for a King. Measure the room before you fall in love with the size, and measure the doorways and stairwells before delivery day.

A king bed is an ideal option for:

Ready to compare? Explore Avocado's certified organic mattresses in King.

A king is 16 inches wider than a queen at the same length (76" x 80" vs. 60" x 80").

For the full comparison from the queen's side, see our guide to Queen Bed Dimensions.

The California king (72" x 84") is 4 inches narrower and 4 inches longer than a standard king. It is not a bigger king—it is a different tradeoff.

Important: King and California king bedding are not interchangeable. Sheets, protectors, foundations, and adjustable bases sized for one will not fit the other. Check dimensions before buying accessories. For the complete breakdown of the longer size, see our guide to California King Bed Dimensions.

A split king is two Twin XL mattresses (38" x 80" each) placed side by side, producing the same 76" x 80" footprint as a standard king. It solves three problems a one-piece king cannot:

Avocado offers split king configurations across our mattress lineup. For the complete breakdown, see: What Is a Split King Mattress?

An Avocado king weighs roughly 110 to 186 pounds depending on the model, from the Eco Organic Mattress (110 lbs) to the Ultra Plush Luxury Organic Mattress (186 lbs). Natural latex is denser than polyurethane foam—that density is part of why it holds its structure for decades while synthetic foams soften and sag.

Because of that weight, king and California king sizes ship via Doorstep Delivery rather than standard parcel carriers, and optional In-Home Delivery & Setup is available in the continental U.S. Every Avocado mattress has handles stitched in for positioning, and should be rotated head-to-foot every six months—never flipped. For exact dimensions and weights by model, see: What Mattress Size Is Best for Me?

At 76 inches wide, a king mattress requires more than a sturdy frame—it needs center support: a center rail with legs to the floor, or a platform engineered to prevent sagging at the middle of the span. This matters more for organic latex mattresses, which weigh substantially more than foam. Avocado's FSC-certified wood bed frames, foundations, and adjustable bases are all built for the weight.

A king is a shared surface — two adults, eight hours a night, in direct skin contact with 6,080 square inches of mattress. Most conventional kings, including the bed-in-a-box models that dominate the category, are built around polyurethane or memory foam, a petroleum-derived material, along with chemical adhesives and synthetic fabrics that can emit volatile organic compounds (VOCs) into bedroom air — and at king scale, that's the largest such surface in the home.

Avocado king mattresses are made instead with certified organic cotton, GOLS-certified organic Dunlop latex or FSC-certified Pure Talalay® latex, and organic wool — along with natural fibers like alpaca and silk in select models — without polyurethane foam, chemical flame retardants, or fiberglass. We also test our core materials for PFAS ("forever chemicals"): 679 substances screened at parts-per-billion sensitivity, with no detectable amounts found.

Those materials do the performance work that conventional mattresses assign to additives — and temperature is where a king proves it, because two sleepers generate twice the heat. Avocado Kings sleep cool by design, not by treatment: organic wool wicks moisture and naturally regulates temperature, latex's open-cell structure breathes while memory foam traps heat, and individually pocketed support coils keep air moving through the core. Those pocketed coils also isolate motion, so one partner's movement doesn't carry over to the other. There are no gel infusions, no "cooling" chemical treatments, no antimicrobial coatings — the performance comes from the fiber, not from something applied to it.

The same materials are the durability case — and a king is the size where it matters most, because it's the largest mattress investment most households make. Every Avocado king is needle-tufted by hand in California — fabric ribbons and wool rosettes secure the layers, not chemical adhesives — and backed by a warranty of up to 25 years, against the seven-to-ten-year lifespan conventional mattresses average. That longevity is also the sustainability argument: an independent 2019 lifecycle assessment found a single Avocado mattress generates roughly 47% less CO₂e over 25 years than the 2.5 conventional mattresses needed to cover the same period.

Every Avocado mattress, including every king, is certified organic under GOTS at the finished-product level. GOTS certifies the entire mattress as it arrives in your home — not individual components inside an otherwise conventional product. It is the standard accepted by the USDA under which textiles (including mattresses) may be sold as organic in the United States: if a mattress is not certified under GOTS, it is not organic, regardless of what the marketing says. GOTS is one of six independent finished-product certifications our mattresses hold:

Explore our certifications to see what each standard verifies.

Product certifications verify the mattress; a separate set of standards verifies the company behind it — which matters when the product carries a warranty of up to 25 years. Avocado is a Certified B Corporation (since 2014, with "Best for the World" recognition), is Climate Label Certified with independently verified emissions accounting for five consecutive years — including a 48% reduction in absolute emissions since 2021 — and is a member of 1% for the Planet, directing 1% of revenue from every mattress sold to environmental nonprofits, more than $12 million since 2017. Every layer of the claim — the product, the materials, and the company — is verified by someone other than us.

Nearly every Avocado mattress model is available in King and California King, from the Eco Organic Mattress to the Grand Luxe, with firmness options from Extra Firm to Ultra Plush, and split king configurations across the lineup.

A king mattress measures 76 by 80 inches—the widest standard size, giving each sleeper the width of a twin. It suits co-sleeping families, restless partners, and bedrooms at least 12 x 10 feet, with a split-king option that adds independent firmness and adjustability.

Choosing a certified organic king means the largest material presence in your bedroom has been independently verified—from the soil the cotton grew in to the finished product in your home—and built to last decades rather than years.

Sleep Better, Naturally: Explore Avocado's Organic Mattresses

A standard U.S. king mattress measures 76 inches wide by 80 inches long.

A king (76" x 80") is 4 inches wider; a California king (72" x 84") is 4 inches longer. King suits couples who want width; California king suits sleepers over 6'2". Bedding for one will not fit the other.

Yes. Two Twin XL mattresses (38" x 80" each) side by side match a standard king's 76" x 80" footprint. This configuration is called a split king.

No. A King and a Queen are exactly the same length — 80 inches. A King adds width only: 76 inches versus a Queen's 60. Shoppers who assume the King is also longer are usually looking for the California King, which is 84 inches long — the longest standard size — but 4 inches narrower than a King. If length for a sleeper over six feet is the goal, choose California King; if shared width is the goal, choose King.

A minimum of 12 x 10 feet, with 12 x 12 feet or larger recommended for comfortable clearance and furniture.

Avocado king mattresses weigh roughly 110 to 186 pounds depending on the model, and ship via Doorstep Delivery rather than standard parcel carriers.

A one-piece king offers a unified surface. A split king lets each sleeper choose their own firmness and adjust their side independently on a dual adjustable base. Couples with different firmness preferences are usually better served by the split king.