The Ultimate Guide to Mattress Sizes – And How They Came to Be

Blog Post by Brian Croft, Owner of Croft Mattress & Founder of Foreverbed

When it comes to buying a mattress, one of the first—and often most confusing—decisions is choosing the right size. Whether you’re shopping for your guest room, your growing teenager, or your forever bed, understanding mattress sizes is essential for comfort, practicality, and space planning.

But have you ever wondered why these sizes even exist? Or how we ended up with names like “king” and “queen” for where we sleep?

As the founder of Foreverbed and owner of Croft Mattress, I’m here to give you a comprehensive—and surprisingly fascinating—look at mattress sizes, past and present.

A Quick Overview of Standard Mattress Sizes

Let’s start with the basics. Here are the most common mattress sizes you’ll find today in the U.S.:

At Foreverbed, we also offer custom sizes for customers who want a truly bespoke sleep experience—because one size doesn’t always fit all.

A Brief History of Mattress Sizes

The Twin Bed: A Start in Simplicity

The twin bed has been around since the early 20th century, designed for efficiency and economy. Originally called a “single,” it was often used in hospitals, dorms, or children’s rooms. Its size made it easy to transport and ideal for tight quarters.

Full Size: The Original “Double”

Before the queen and king became popular, the full—or double—was the standard size for couples. But at just 54 inches wide, that left each person with less space than a crib mattress. No wonder so many couples started looking for something bigger.

Queen and King: Fit for Royalty

The queen and king sizes didn’t really hit the mainstream until the 1950s and ’60s. As American homes got larger post-WWII, so did our appetite for space—and our beds followed suit. The queen became the new standard for couples, while the king catered to those craving room to sprawl.

The California King, despite its name, was invented by a Los Angeles mattress company in the 1960s. It was designed for the Hollywood elite who needed longer (and more luxurious) beds to fit their upscale aesthetics and towering ceilings.

International Mattress Size Confusion

If you’ve ever tried to fit U.S. sheets on a European mattress, you’ve learned the hard way that sizing is not universal. For example:

• UK King = 60” x 78” (shorter than U.S. King)
• European Double = 55” x 79”
• Japanese Semi-Double = 48” x 77”

At Foreverbed, we’ve helped many customers moving internationally—or outfitting vacation homes—navigate these cross-border challenges.

Choosing the Right Mattress Size

When selecting your mattress size, ask yourself:

1. Who’s sleeping on it?
   One person, a couple, or a rotating cast of pets and toddlers?
2. What’s the room size?
   A king in a tight room might feel cramped. Measure first.
3. How do you sleep?
   Toss and turn? Go bigger. Like to be cozy? Queen may suffice.
4. Future-proofing?
   Teenagers grow. Guest rooms evolve. Consider what lies ahead.

Custom Sizes for a Custom Life

At Foreverbed, we recognize that not every bed should fit a mold. Whether you need an Olympic Queen (66” x 80”), a split configuration, or a totally unique shape, we can handcraft the right size for your lifestyle—and your space.

In Conclusion

Mattress sizes might seem straightforward today, but they’re the result of decades of evolving habits, home design, and human needs. As homes got bigger, our beds followed. And as our lives become more personalized, so should our mattresses.

If you’re looking for guidance, our team at Croft Mattress and Foreverbed is here to help you find—or design—the perfect fit.