woman trying to measure a mattress
Bedroom Design

How To Measure A Mattress Correctly

  •  Purple Author Icon
    Last Updated
    May 16, 2023
    min read

    Unsure how to confirm the size of your mattress? All you’ll need is a tape measure or ruler to accurately measure. 

    In this article, we’ll discuss how to measure your mattress properly and how to match your mattress measurements to the standard mattress sizes plus a few additional considerations after you’ve confirmed your measurements.

    Looking for a new mattress that perfectly fits your room size? Check out our Purple mattresses with GelFlex Grid technology! All mattress orders come with free shipping directly to your door.

    How To Measure A Mattress

    You can measure a mattress by using a measuring tape or ruler to get the width, length, and height. Here’s a step-by-step guide that breaks down the process:

    Remove All Bedding

    Before breaking out the tape measure, remove all bedding. This includes sheets, comforter, blankets, and pillows. If you have a mattress pad, protector, or separate foam topper, remove those as well.

    Measure Your Mattress

    Now that you’ve removed all bedding, it’s time to measure your mattress’s dimensions. A  tape measure works best, but a ruler will work in its place. Here’s how:

    • Measure left to right for width: Using your tape measure, measure from the left edge of your mattress to the right edge. Note the measurement in inches. This will be the width of your mattress.
    • Measure front to back for length: Using your tape measure, measure from the head of your mattress to the foot. Note the measurement in inches. This will be the length of your mattress.
    • Measure from top to bottom for thickness: Using your tape measure, measure from the top of your mattress to the bottom. Note the measurement in inches. This will be your mattress thickness. Most mattresses are between 10 and 12 inches thick. If you have a mattress pad, protector, or separate foam topper, take additional measurements of the height with those accessories in place on the mattress. This will be the encasing depth of your mattress, which determines the correct sheet dimensions needed.

    The ideal height of your mattress depends on a myriad of factors. Read our guide on how to find the best bed height for you.

    Match Your Mattress Measurements With The Mattress Size

    There are six standard mattress sizes: twin, twin XL, full, queen, king, and California king. These standard sizes are categorized by the width and length measurements of a mattress. However, these sizes can vary slightly between different brands.

    It’s important to keep in mind that there is no standard measurement for the thickness of a mattress. You can find a mattress with the ideal mattress height for you from most mattress stores.

    Refer to the chart on mattress sizes below:

    Mattress size

    Measurements (width x length)


    38 x 75

    Twin XL

    38 x 80


    54 x 75


    60 x 80


    76 x 80

    California king

    72 x 84

    Split king

    38 x 80 (per mattress)

    A split king bed is two twin beds together on one foundation, allowing for two sleepers to experience two separate mattresses. Learn more about tying two twin beds together in our blog.

    Want to know more about the different mattress sizes? Check out our mattress size chart and bed dimension guide

    Additional Facts To Consider

    Before committing to a mattress, there are a few things you should keep in mind.

    Measure Your Room

    Do you have enough space in your bedroom for your desired mattress? To find out if a mattress will properly fit in your room , measure the floor space of your bedroom as well as the dimensions of any other furniture in the room.

    Be sure to leave adequate space around your mattress for movement. It’s almost important to take  into account the size of other furniture in the room like tables and chairs. If your mattress is too big, your room will feel small and cramped. Conversely, a mattress that’s too small can make your room feel a bit empty or too spacious.

    Got questions about the right mattress size for your room? Learn what size bed you should get and the optimal position for it in your bedroom.

    Measure Your Bed Frame

    Measure your bed frame to match the size of your mattress. Keep in mind that bed frame sizes tend to run a few inches longer and wider versus standard mattress sizes. 

    Measure Your Hallway And Doorways

    While your room size is the primary factor to consider when choosing a new mattress, you should also keep in mind  the size of your hallways and doorways. Measure the height and width of the hallways and doorways that your  mattress must travel through in order to get to its final placement. If your desired mattress size is too big to fit through hallways or doorways,  opting for a smaller-sized bed may be best.

    Measuring Mattress FAQs

    How to know what size bed you have?

    To know what size bed you have, compare your mattress’s width and length with our mattress size chart. Match your dimensions to the standard sizes on the chart. For example, if your mattress is 60 inches wide by 80 inches long, it’s a queen-size mattress.

    How to measure bed size?

    You can measure your bed size by using a tape measure or ruler. Measure from the left edge to the right edge to get the width. Measure from the head of the bed to the foot to get the length. You can also measure the mattress from top to bottom to get its height.


    About the authors

    Purple Staff
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