Quick Answer: A California king mattress measures 72 x 84 inches (narrower and longer than a standard king). The matching box spring must be the same exact dimensions. Cal king is significantly less common in Canada than standard king — confirm mattress, foundation, frame, and bedding availability before committing to this size in Ontario.
In This Guide
Reading Time: 7 minutes
The California king is the longest standard mattress size manufactured. At 72 inches wide by 84 inches long, it provides 4 more inches of foot clearance than a standard king, which makes it the choice for households where height is a real issue at night. But in Canada, the California king brings practical sourcing challenges that buyers should understand before committing.
This guide covers the California king mattress and box spring system as a complete setup: dimensions, availability in Ontario, foundation options, and who this size actually suits.
California King Dimensions and Setup
| Component | California King | Standard King |
|---|---|---|
| Mattress | 72" x 84" | 76" x 80" |
| Box spring | 72" x 84" | 76" x 80" |
| Frame | California king specific | Standard king |
| Headboard | California king specific | Standard king |
| Fitted sheets | California king specific | Standard king |
| Minimum room size | 12' x 12' recommended | 11' x 11' recommended |
Every component of a California king bed is size-specific. The box spring, frame, headboard, and all bedding must be California king dimensions. Standard king accessories do not fit and cannot be adapted. This is the most common purchasing error: buying a California king mattress and attempting to use standard king bedding or a standard king frame.
Availability in Canada and Ontario
California king is an American-originated size. The United States market drives production volume for this size. Canadian retailers and distributors source Cal king product from the same supply chains, but with significantly lower demand, which means:
- Fewer models available in Cal king than in standard king or queen
- Longer lead times for ordered-in models (2 to 6 weeks versus in-stock)
- Higher prices in some cases due to lower production run volumes
- Limited availability of Cal king bedding (fitted sheets, mattress protectors, duvets) at local stores
Cal King in Ontario: What to Expect
In the Brantford and broader Ontario market, most mattress retailers stock standard king (76 x 80 inches) as their largest offering. California king may be available as a special order. If you are considering this size, call ahead to confirm availability before visiting, and ask about lead times for both the mattress and the matching foundation. The Mattress Miracle team can advise on whether a Cal king is practical for your needs or whether a standard king serves you better. Call us at (519) 770-0001.
Foundation Options for California King
California King Foundation Options
- California king box spring (72 x 84 inches): Must match exact dimensions. Low-profile versions (5 inches) recommended with modern 10-12 inch mattresses to keep total height comfortable.
- California king platform frame: Available from major furniture retailers and some mattress retailers. Solid or slatted designs provide equivalent support without a box spring.
- Adjustable base (California king): Available but with very limited selection compared to standard king adjustable bases. Confirm motor and remote compatibility before purchasing.
- Custom wooden foundation: A DIY option using 2x6 lumber to exact Cal king dimensions (72 x 84 inches) if sourcing a manufactured foundation proves difficult locally.
Who Should Choose California King vs. Standard King
| Choose California King if... | Choose Standard King if... |
|---|---|
| At least one sleeper is 6'2" or taller | Both sleepers are under 6'2" |
| Foot clearance at night is a consistent problem | Width for two sleepers is the priority |
| Room depth (door-to-wall distance) is at least 12 feet | Room is wider than deep |
| You are willing to source Cal king bedding specifically | You prefer standard bedding availability |
Complete Setup Checklist
Before purchasing a California king mattress and box spring:
- Confirm your room accommodates 72 x 84 inches plus walkway clearance (at least 24 inches on each side)
- Confirm the mattress is available in California king with your preferred brand
- Confirm the box spring or foundation is available in California king dimensions
- Confirm the bed frame is California king specific (not adjustable for standard king)
- Confirm California king fitted sheets and protectors are available from your preferred supplier
- Confirm delivery access: a 72 x 84 inch mattress requires manoeuvring through doorways and up stairs
For related information on setting up large bed sizes, see our guide to California king box spring dimensions and our overview of bedroom mattress sets.
Shop: King Mattresses at Mattress Miracle
Find Your Perfect Mattress at Mattress Miracle
We are a family-owned mattress store in Brantford, helping our community sleep better since 1987. Come try mattresses in person and get honest, no-pressure advice.
441 1/2 West Street, Brantford, Ontario
Call 519-770-0001Frequently Asked Questions
What are the dimensions of a California king mattress and box spring?
A California king mattress measures 72 inches wide by 84 inches long (183 cm x 213 cm). The matching box spring must be the same dimensions. California king is 4 inches narrower and 4 inches longer than a standard king (76 x 80 inches). All accessories including the frame, headboard, and bedding must be California king specific.
Is a California king box spring and mattress available in Canada?
California king mattresses and box springs are available in Canada but with significantly less selection than standard king sizes. Most Canadian retailers stock standard king as their largest size. Expect longer lead times and fewer model options for California king in Canada.
Do I need a box spring with a California king mattress?
A box spring is not required for a California king mattress. A platform frame or slatted base designed for California king dimensions provides equivalent support. If your frame was designed for a box spring, confirm whether a low-profile rigid foundation will fit before purchasing.
Who should choose a California king over a standard king?
The California king is best suited for households where at least one person is 6 feet 2 inches or taller. For couples where height is not a concern, a standard king (76 x 80 inches) offers 4 more inches of shared width, which is typically more useful for two-person sleeping.
How do I shop for a California king mattress and foundation in Ontario?
In Ontario, California king availability varies significantly by retailer. Confirm that both the mattress and foundation are in stock before purchasing one or the other. Some Ontario retailers can order Cal king models with a 2 to 6 week lead time. Always confirm bedding availability before committing to this size.
Sources
- Radwan A, et al. (2015). Effect of different mattress designs on sleep quality and spinal alignment. Sleep Health, 1(4), 257-267. doi.org/10.1016/j.sleh.2015.08.001
- Health Canada. (2021). Consumer Product Safety — Mattresses. canada.ca/health-canada
- Sleep Foundation. (2023). California King vs King Mattress Size Guide. sleepfoundation.org
- Lahm R, Iaizzo PA. (2002). Physiologic responses during rest on a sleep system at varied degrees of firmness. Ergonomics, 45(11), 798-815.
Visit Our Brantford Showroom
We are located at 441½ West Street in downtown Brantford. Free parking available. Our team does not work on commission, so you get honest advice based on your needs.
Mattress Miracle — 441½ West Street, Brantford, ON — (519) 770-0001
Hours: Monday–Wednesday 10am–6pm, Thursday–Friday 10am–7pm, Saturday 10am–5pm, Sunday 12pm–4pm.
If you are considering a California king and are unsure whether it makes sense for your room size and sleep needs, come in and we can walk you through the dimensions and alternatives. We have been helping Brantford families with larger-format sleep setups since 1987.