How Long Is a Full Size Mattress? Dimensions, Fit, and FAQs
If you’re asking “How Long Is a Full Size Mattress”, you’re usually trying to figure out whether it will fit you and your space. This guide breaks down standard full size mattress dimensions, how they compare to other sizes, and what to consider before choosing one.
What Are the Standard Dimensions of a Full Size Mattress?
In most cases, a full size mattress (also called a double) measures:
- Width: 54 inches (about 137 cm)
- Length: 75 inches (about 191 cm)
So when you ask “How Long Is a Full Size Mattress”, the standard answer is:
➡️ A full size mattress is typically 75 inches long.
These dimensions are widely used across many mattress manufacturers, especially in the U.S. and Canada.
Why Does the Length of a Full Size Mattress Matter?
The length of a mattress affects:
- Comfort for taller sleepers – People over a certain height may find their feet close to or hanging off the edge.
- Room layout – Knowing “How Long Is a Full Size Mattress” helps you plan where to place the bed, nightstands, and other furniture.
- Bedding fit – Standard full size sheets, protectors, and toppers are designed around the 54" x 75" size.
In general, a full size mattress is often considered a good match for:
- Single adults under about 6 feet tall
- Teens and older children
- Smaller guest rooms or studio apartments
How Does a Full Size Mattress Compare to Other Mattress Sizes?
Understanding how a full size compares to other common sizes can help you decide if it’s long enough for your needs.
| Mattress Size | Width x Length (inches) | Notes |
|---|---|---|
| Twin | 38" x 75" | Same length as full, narrower |
| Twin XL | 38" x 80" | 5" longer than full |
| Full (Double) | 54" x 75" | Wider than twin, same length |
| Queen | 60" x 80" | Wider and longer than full |
| King | 76" x 80" | Much wider, same length as queen |
Key takeaway: A full mattress is not as long as a queen, king, or twin XL.
It has the same 75" length as a standard twin.
Is a Full Size Mattress Long Enough for Tall People?
This is one of the most common questions behind “How Long Is a Full Size Mattress”.
- For sleepers under or around 5'9"–5'10", a full is often comfortable in length.
- Taller individuals may feel more comfortable on a twin XL, queen, or king, which are typically 80 inches long.
If you’re tall and still considering a full, it can help to:
- Lie down and check whether your head and feet both rest comfortably on the mattress
- Consider your preferred sleeping position (for example, those who sleep fully stretched out may need more length)
Do Full Size Mattresses Ever Vary in Length?
Most full size mattresses follow the 54" x 75" standard, but small variations can occur:
- Some models may be off by an inch or so due to materials and design.
- Mattresses with thick pillow tops or specific constructions may feel slightly different in size when measured from edge to edge.
For bed frames and bedding, relying on the standard 75-inch length is usually safe, but checking product dimensions can help avoid surprises.
How Much Space Does a Full Mattress Take Up in a Bedroom?
Knowing “How Long Is a Full Size Mattress” also helps you plan your room layout.
A 54" x 75" mattress is often recommended for:
- Small to medium bedrooms
- Rooms where you want extra floor space around the bed
- Guest rooms that need a comfortable sleeping surface without dominating the space
When planning your layout, remember to add extra length for:
- Headboards or footboards
- Clearance around the bed for walking
- Any storage or benches placed at the foot of the bed
✔️ Quick Mattress Takeaways
Key points about “How Long Is a Full Size Mattress”:
- Standard full size length:75 inches
- Standard full size width:54 inches
- A full size mattress is the same length as a twin, but 16 inches wider.
- Taller sleepers often prefer twin XL, queen, or king for extra length (typically 80").
- Full size mattresses work well for single adults, teens, and guest rooms where space is limited.
- Small variations in dimensions can occur between models, so checking exact measurements is helpful for tight spaces or custom frames.
Understanding how long a full size mattress is makes it easier to match the bed to your height, your room size, and your comfort preferences. With the standard 54" x 75" dimensions in mind, you can more confidently decide whether a full is the right fit for your sleep space.
