
Standard comforter sizes can vary from one manufacturer to another. This discrepancy is because some manufacturers produce comforters sized specifically for pillow top or deep mattresses. This difference in size can vary as much as eight to 12 inches more than older comforters. If you have a newer mattress set, then this won't be a problem for you but if you're sleeping on a pre-pillow mattress set, then you'll need to pay attention to the comforter sizing information.
Standard Mattress and Comforter Size Estimates
When searching for standard measurements for comforters, you'll quickly discover there are no true standards. In fact, you can find different sizes for a twin, twin XL, full, queen, king and California king. These measurements can vary as much as 12 inches from one manufacturer to another. It's best to always double-check the details of a comforter to verify the sizing prior to purchasing.
This chart gives a rough estimate of mattress sizes and corresponding comforter size:
Comforter | Mattress Size | Comforter Size |
Standard Twin | 39" x 75" | 68" x 88" |
Twin (XL-adult) | 39" x 80" | 68" x 88" |
Full (double bed) | 54" x 74" | 80" x 90" |
Queen | 60" x 80" | 86" x 94" |
King | 78" x 80" | 88" x 102" |
California King | 72" x 84" | 96" x 110" |
Things to Consider Before Buying
The most important thing to consider before committing to purchasing a comforter is to understand what the manufacturer considers a standard mattress size. Twin and king size mattresses come in two sizes, a pillow-top mattress can affect your final size of comforter, and you'll want to pay attention to whether your comforter is down-filled.
Twin Size Mattress
You may not be aware that twin size mattresses come in two sizes. This is something you'll want to double check whenever purchasing a twin-sized comforter.
- The standard twin size comforter is typically the size purchased for a child's room.
- The twin XL is considered the twin size for an adult. It's the size often found in college dorms. This twin size has an addition five inches in length.
The comforter size should allow for the extra length and width of material needed to fall over and conceal the top mattress and box springs. Check the overall dimensions stated on packaging or within the website description.
Keep in mind, some manufacturers don't make any distinction between a standard twin size and a long twin size. In fact, many twin size comforters will fit both twin and twin XL mattresses. Check sizing on the package or description before you buy.
King Mattress
The king size mattress also comes in two sizes: king and the California king.
- The king size mattress is wider, but not a long as the California king.
- The California king is longer but not as wide as the king.
- Sheets must be produced specifically for a king or California king; however, this isn't always the case for some comforter manufacturers.
Many comforter manufacturers produce only one size for king mattresses and use a standard of 96" x 110" for both king and California king. This is just one more reason why it's important to know the actual measurements of your mattress and the comforter dimensions.
Down-Filled Comforters
If you want to purchase a down-filled comforter, you may need to select an oversized one. The down will fill out the comforter and may slightly reduce the fabric coverage over your mattress.
Comforters for Pillow-Top Mattresses
The majority of comforters being manufactured today are designed for pillow-top mattresses. Some mattresses have a pillow top on both sides of the mattress since the correct way to use the mattress is to flip it over every month or two. This kind of double pillow top mattress obviously creates extra thickness that requires deep pocket sheets.
This extra depth needs to be accommodated by extra comforter material or the comforter won't fit the sides and bottom of this type of mattress.
- For a 10" deep mattress, you'll want to double check the comforter width to determine if it will cover both the top mattress and box springs.
- A platform bed will only have a top mattress. The comforter size needs to be smaller than one large enough to fit a traditional bed with box springs and a pillow top mattress.
By the same token, if your mattress isn't a deep pocket or pillow top, the comforter could be too long for your bed. Mattress measurements are vital for a perfect fit.

Measure Your Mattress
Before making a purchase, you need to measure your mattress so you can work with exact dimensions. This will eliminate possibly purchasing the wrong size comforter and being disappointed when it doesn't completely conceal your mattress, and in some cases, box springs. Once you've measured your mattress, you'll quickly discover if it falls within standard sizings.
Mattress Depth Ranges
A pillow top mattress or an extra deep mattress can become a point of competition between mattress manufacturers, so this can create even greater inconsistencies in actual mattress depths.
One standard that you can use is a range of mattress depths. For example:
- A standard pillow top mattress can be anywhere between 7 to 8 inches deep.
- A deep mattress is considered between 10 and 16 inches.
- An extra deep one can be as much as 22 inches deep.
How to Measure
The depth of a mattress will greatly affect the way a comforter covers the mattress so the safest thing to do is to take a few measurements.
- Measure the length and width of your mattress since many manufacturers produce oversized comforters. This can be especially true of down-filled comforters.
- Once you have these two measurements, take a third measurement of the mattress depth (height).
- Add the depth to both the length and then the width.
- If you prefer the comforter to fall beyond the box springs, add the necessary inches to your overall figures.
Choosing the Right Size
The most important thing you need to keep in mind while shopping for a comforter is the exact comforter size. Using the mattress measurements you took, you can easily determine whether or not a comforter will fit your mattress. By taking time to measure and confirm the size of a comforter, you'll end up with the perfect comforter for your bed.