King vs. California King Mattresses: What's the Difference? (2024)

Mattresses are highly customizable: Choose your firmness, materials, extra features and even delivery methods (hey there, mattress-in-a-box). But the first choice you're probably going to make is size. After all, a twin mattress won't work for a couple, and the mattress must also fit into your bedroom. If you're looking for a large or oversize mattress, you've likely come across the terms king mattress and California king mattress. So what is the difference between the two? Our experts can explain.

The Good Housekeeping Institute Textiles Lab is full of fiber scientists who are constantly testing to find the best mattresses, best sheets, best pillows and more. They've tested and evaluated hundreds of mattress models to find the best recommendations for every type of sleeper. In the past three years, they've surveyed more than 10,000 mattress owners and reviewed answers to more than 170,000 questions. We asked them to share how to decide whether a king or California king is right for you.

You probably already know the answer: size. A king mattress is wider and shorter, while a California king is thinner and longer. Though most people think a California king mattress is bigger than a king, it's actually smaller in terms of square footage. The footprint of each mattress is different so you have to determine which is better suited to the space you have.

Below, we've included our best overall pick (the Saatva Classic Mattress) and best value pick (the Allswell Luxe Hybrid). Our top performers don't change based on mattress size, so both are great options in any size you decide.

A standard king mattress is the largest common mattress on the market. The best way to think of the dimensions of a standard king is that it's the size of two twin mattresses. It can fit multiple sleepers — often two adults though it can accommodate children or pets.

A standard king mattress is usually 80 inches long by 76 inches wide. It's a wider option, one that Lexie Sachs, executive director of the Good Housekeeping Institute Textiles, Paper & Apparel Lab, prefers since she has two kids. But if you are over six feet tall (a.k.a., 72 inches), you might find your toes hanging off the end of the bed in the middle of the night.

Pros:

• Wider than a California King
• Easier to find
• Ideal for shorter and wider rooms

Cons:

• Might not fit tall sleepers

A California king is narrower than a king, yet most people think the mattress is bigger because it's longer. A good way to think of the dimensions of a California king mattress is to think of the state in its name: taller than it is wide. It's ideal for taller people, though you might find a tight fit if there are any kids or pets hopping into bed with you.

A California king is usually 84 inches long by 72 inches wide. This means if you're six feet tall, you've got plenty of extra space (12 inches to be exact) to move around without your toes going cliff-jumping. But you are losing four inches on the width of the mattress.

Pros:

• Longer than a standard king
• Ideal for people over six feet tall
• Better for narrow rooms

Cons:

• Not as common as a standard king
• Might be more expensive, depending on the brand

The primary considerations are the dimensions of the room and the sleeper's height. In general, the shape of the mattress should match the shape of the room, depending on where the bed is to be located. For example, if you have a room that is 14" x 16" and you can put your bed along either length, a king mattress would work well with the headboard against the wider wall, and a California king would work well with the headboard against the narrower wall. The second thing to consider is height. If anyone using the bed is over six feet tall, you have to decide what's more important: how the bed fits in the space or how you fit in the bed.

Something else to keep in mind is while it isn't terribly hard to find sheets and pillows for a California king, they still aren't as common as bedding that fits a standard king. More specialized items like a bed frame, box spring or mattress protector can be harder to find for California king. California king options are usually more expensive too.

Unfortunately, no. Because the dimensions don't match, the end of the mattress would hang off the end of the frame, which isn't good for the mattress. If you already have a king-size bed frame and don't want to replace it, stick to the standard king mattress. If you're looking to change everything over though, you can start by checking out our guides to the best bed frames. There are plenty of options for bed frames that are under $300, or you can opt for luxury and snag an adjustable bed frame.

Yes! Most comforters come in combined sizing: Twin/Twin XL, Full/Queen, and King/CA King. Comforters drape over the edge of the bed so there's usually enough fabric for versatility. Sheets are a different story, particularly the fitted sheet. If you want a good, snug fit on your sheets, it's best to go with the specific size and not a combined option.

Need some inspo for your new bedding look? We've got articles on the best comforters, best bedding sets, best duvet inserts and best duvet covers.

Why trust Good Housekeeping?

The Good Housekeeping Institute Textiles Lab has been evaluating bedding and home products for over a century. Since the online mattress industry's rapid expansion in 2014, our experts have actively researched and reviewed hundreds of models, surveyed thousands of our readers and analyzed countless data points to find the best mattresses available.

Abigail Bailey (she/her) covers everything from kitchen gear to mattresses for the GH Institute, and she assists the General Manager with any number of projects. She graduated from Louisiana State University with a B.A. in creative writing, and she earned her M.S. in publishing digital and print media from New York University.