When shopping for a new mattress topper, nailing down the right size can be tricky. You want your topper to fit the mattress properly without being too small and leaving gaps or too large with excessive overhang. But is it better for your topper to run a little large or a little small?
This article examines the pros and cons of having a mattress topper that’s slightly undersized or oversized. We’ll provide tips on measuring your mattress, finding the ideal topper dimensions, and working with a topper that’s not a perfect match.
Benefits of an Oversized Mattress Topper
Having a mattress topper that’s slightly larger than your mattress does offer some potential perks:
No Gaps in Coverage – The excess overhang prevents any gaps along the edges or corners so you have full coverage across the mattress surface.
Accommodates Deep Mattresses – Thick luxury mattresses over 12” deep may require an oversized topper for proper fit.
Allows for Shrinkage – Natural fibers like wool and cotton shrink slightly when washed. A larger size maintains coverage through cleaning.
Stays In Place – The topper tucking under on all sides helps keep it more securely in position rather than sliding around.
Provides a Lifted Edge – The overhanging sides create a subtle “lip” around the topper edge that makes getting in and out of bed easier.
In certain situations, having a mattress topper extend past your mattress can be beneficial and cause little issue. But potential drawbacks exist as well.
Drawbacks of an Oversized Mattress Topper
While nice in some cases, using an oversized mattress topper also comes with these disadvantages:
Fit Issues With Sheets – Deep pocket sheets may be required to accommodate the thicker profile, especially with overhang. Regular sheets could pop off the edges.
Can Look Messy – Excess material bunching up around the sides of your bed has a messy, unkempt appearance.
Trip Hazard – Topper overhang along the sides of the bed creates a tripping hazard. Toes could get caught walking past.
Compressed Edges – Sitting on the edge of the bed compresses and flattens the excess overhanging topper material. This reduces support.
Traps Heat – More surface area, especially with memory foam toppers, could potentially trap extra heat and make you sleep hot.
Reduces Mattress Lifespan – If you sink in too far overall, it could damage lower mattress layers and materials prematurely.
Take steps to minimize drawbacks if your topper runs slightly large for your bed. Next we’ll look at benefits of an undersized topper.
Benefits of an Undersized Mattress Topper
A mattress topper that’s a bit narrower and shorter than your mattress also has some advantages:
Fits Standard Sheets – Most sheets fit better without excess loft and overhang around the edges. Undersized prevents sheet popping.
Safer Edges – Less risk of tripping on looser material around the sides. Easier to get in and out of bed.
No Compression Defects – No compressed, flattened edges since the topper stays completely on the mattress surface.
Limits Heat Retention – The smaller surface area doesn’t trap as much body heat. This prevents overheating for hot sleepers.
Prevents Premature Mattress Wear – With no excess sink and compression, your mattress lasts longer before materials soften and wear down.
Looks Neat and Tidy – A topper that fits the contours of your mattress has a tidier, tailored appearance. No messy overhang.
In many ways, a less voluminous topper prevents issues like poor sheet fit, trip hazards, and heat buildup. But some cons with undersized exist too.
Drawbacks of an Undersized Mattress Topper
While an undersized mattress topper can work well in some cases, potential drawbacks include:
Gaps in Coverage – Not wide or long enough means gaps form around the edges or corners that are not cushioned and softened by the topper.
Compromised Comfort – For sleepers who use the whole surface of the bed, gaps mean missing out on pressure relief in certain areas.
Prone to Shifting – Without tucking under the mattress, undersized toppers may be more likely to slide around or get ruffled up.
Not Secured in Place – Lack of overhang allows the topper to move freely since it’s not anchored underneath the mattress edges.
Insufficient Edge Support – No extra loft around the perimeter fails to build up the edges and make getting in and out easier.
Reduced Performance – Certain tops like cooling gel toppers work better when covering the mattress fully edge-to-edge.
Take precautions like anchoring and smoothing to prevent undersized topper issues. Next we’ll look at how to measure correctly.
Measuring Your Mattress Correctly
Measuring properly ensures ordering the right topper size:
- Measure length and width carefully edge-to-edge. Include any space the bed frame takes up.
- For deep mattresses, factor in extra height above 15 inches that may require oversized length and width.
- Stand on the bed to depress surface and simulate body impressions during measuring to get accurate dimensions.
- Round up to the nearest whole inch or size when ordering. It’s easier to work with a topper slightly large versus slightly small.
- Refer to the manufacturer’s size chart and recommended topper dimensions for your particular mattress model.
Taking accurate measurements of your mattress and bed frame space ensures getting a properly sized topper.
Finding the Right Topper Size
To choose the optimal topper size:
- Look for a topper with the same length and width or up to 2 inches longer and wider than your mattress size.
- Toppers for Twin, Twin XL, and Full mattresses should match mattress dimensions precisely. Oversizing isn’t necessary.
- For King and Queen sizes, upsize 1 to 2 inches for enough overhang to anchor underneath but not bunch excessively.
- Add 2 inches to length and width for mattresses over 14” deep to accommodate the extra loft.
- Size up for natural material toppers like wool, cotton, and feathers that shrink slightly after washing.
Getting topper dimensions right from the start prevents having to exchange an improperly sized topper later on.
Making a Poor-Fitting Topper Work
If your topper ends up slightly too small or large:
For an Oversize Topper:
- Use deep pocket sheets to fit the thicker profile.
- Tuck excess material under mattress smoothly to prevent bunching.
- Place a foam bumper under edges to avoid compression.
- Add a mattress pad on top to secure the topper perimeter.
For an Undersized Topper:
- Fill in gaps with pillows or rolled-up blankets as needed.
- Use elastic straps to securely anchor the topper in place.
- Activate “grip dots” underneath by simply wetting them first.
- Place on top of a mattress pad for added friction and to smooth edges.
Get creative with easy fixes to make a less-than-perfect sized topper work great for your bed.
FAQs About Mattress Topper Sizing
How much larger should a mattress topper be?
1 to 2 inches longer and wider is ideal for most Queen and King size mattress toppers. This prevents both excessive overhang or undersized coverage gaps.
Do mattress toppers come in standard sizes?
Yes, mattress topper sizes correspond directly to standard mattress sizes. Just measure correctly and order the matching size or size up 1 inch for best fit.
Should you get a bigger topper for a thick mattress?
For mattresses over 14” deep, sizing up the length and width of your topper 2 inches accommodates the extra loft height better with sufficient overhang.
Can you trim a memory foam topper to size?
Trimming a memory foam topper is not recommended. This can compromise its structure. Return or exchange for a properly fitting size instead.
How can I stop a mattress topper from sliding?
Using a fitted sheet, mattress pad or anchor straps to secure your topper helps keep it from sliding around on the bed if it’s undersized or slick.
Getting the right mattress topper length and width for your particular mattress ensures the best fit. Measure carefully and size up for plenty of overhang on Queen, King, and oversized mattresses. For undersized toppers focus on anchoring techniques. With a properly fitting topper you’ll get relief from head to toe!
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