Insole Measurement - How to Measure Insoles for Shoes?

By Josh White DPM  /  August 29, 2023 Blog Home

Whether you're trying a new shoe brand or buying your shoes online, having accurate insole measurements can make all the difference in achieving the perfect fit. But, that’s just one benefit of knowing your insole measurement, because when you need over the counter orthopedic insoles, you will have to know your size. 

What are insoles, you ask? Simply put, insoles are sheets that are placed inside shoes to provide cushioning, support, and comfort. They can be made from a variety of materials, including foam, gel and even leather. 

Insoles can be custom fitted to provide specific support for certain foot conditions, such as flat feet or high arches, but you can also find over the counter insoles for plantar fasciitis or a large variety of other conditions. They can also be used to improve athletic performance by providing additional cushioning and support.

Insoles are a great way to improve the comfort and fit of your shoes. They can also help to prevent foot pain and injuries. If you are experiencing any foot pain, or if you simply want to improve the comfort of your shoes, insoles are a great option.

So, now that we got our definitions straight, let's explore the mystery of insole measurements and discover how they can significantly impact your overall shoe wearing experience, and your foot, leg and back health. 

Do insoles have sizes?

Yes, insoles typically come in sizes, just like shoes. Actually, sizing plays a crucial role in ensuring the perfect fit and optimal comfort for your feet. 

Insoles come in two types of lengths: 

  • a full length insole that spans from the heel to the toes, covering the entire length of the shoe; 
  • conversely, a ¾ length insole typically reaches up to the ball of the foot region.


The decision between these two options relies on whether your shoes have a removable footbed or are too narrow at the front to accommodate an insole. For instance, shoes like pumps or ballet flats often lack a removable footbed and have a narrower forefoot design. This construction creates a limited space, only allowing for a shorter orthotic for proper fit and comfort.

The sizing of full length insoles is typically indicated as a shoe size for men and women, allowing for compatibility with a variety of footwear that come with a removable insole. But, it's important to note that different manufacturers might utilize varying sizing conventions. 

Navigating the insole sizing landscape can be straightforward, even if you find yourself between sizes. In such cases, a general rule of thumb is to size up to the nearest half size. This ensures that you enjoy the full benefits of the orthopedic insoles' support and comfort without any compromises.

¾ length insoles are designed to fit into shoes that already have an internal liner, unlike full length insoles that substitute the shoe's liner entirely. Even though ¾ length insoles are, well, not the full length of the foot, the size range associated with these insoles reflects the footwear sizes in which they can be used comfortably. 


How to measure your insole?

To measure your insole size, follow these steps:

  1. Choose your most comfortable and well fitting pair of shoes and place them flat on an even, flat surface.
  2. With a flexible tape measure, insert the end marked with 0 all the way into the tip of the toe inside the shoe.
  3. Lay the tape along the inside of the shoe, extending it to the inner part of the heel and flattening it against the shoe's bottom. This measurement indicates the actual length of the insole in inches.
  4. Repeat steps 1 through 3 in your other shoe, to make sure there are no significant differences.
  5. If the measurement falls between half sizes, round it up to the closest ½ inch value. For instance, if you measure 8.25 inches, round it up to 8.5 inches.


You can also measure your feet directly. Here’s how:


  1. Prepare a sheet of paper and place it on the floor.
  2. Stand on the paper with your foot, ensuring your weight is evenly distributed.
  3. Hold a ballpoint pen vertically and use it to trace the outline of your foot's contour on the paper. If possible, ask another person to trace your foot’s outline to get more accurate results. 
  4. Carefully remove your foot from the paper.
  5. Locate the point on the traced outline where your foot's length is at its maximum.
  6. Use a ruler or a measuring tape to measure the distance from the tip of your longest toe to the point of maximum length on the traced outline. This measurement in inches is the length of your foot.
  7. Repeat with your other foot, as our feet tend to be of slightly different sizes.


And here’s a tip: measure your feet at the end of the day, when they are more swollen. Feet tend to swell throughout the day, making your feet their largest in the evening. It's better to have slightly larger shoes that can accommodate insoles than shoes that are too tight.


What size shoe to buy for insoles? Should you size up or down insoles?

It's crucial to select insoles that provide a comfortable fit. 

If your shoes are intended to accommodate custom or standard insoles, it means they are designed with removable footbeds and there's no need to purchase larger footwear to accommodate them.

Note that sometimes, when you use new insoles, it might be a good idea to wear them for a few hours each day and gradually increase your shoe inserts’ duration, until you feel comfortable wearing them all day long. It may take up to 6 weeks for some people to fully adjust to their new insoles.

If your insole isn't providing comfort within a few weeks and your shoes feel tighter, it could mean that the insole is not suitable for your specific shoes or feet. It might also suggest that the insole was not manufactured correctly or there could be an issue with it.


Do insoles fit in any shoe?

If your shoes come with removable built in insoles, it's likely that you can easily fit your custom or over the counter insoles for added comfort. 

If you want to use the same insoles in multiple pairs of shoes, just make sure they'll fit and work well in each new pair. Different shoe brands and styles have different constructions, so it's important to check that your insoles will still provide the support you need.

To evaluate the fit, gently place your hand into the front of the shoe and see how well the length and width of the insole align with the shoe's dimensions. 

A properly fitting insole should lie seamlessly and evenly on the shoe's base, without any uneven tilting. If you notice any protrusion or space between the orthotic and the shoe's sides, this indicates a mismatch in fit. 

An improperly fitting orthotic might shift or alter its shape within the shoe, undermining the vital support it is designed to provide.


Do insoles make shoes smaller?

Inserting insoles can impact the available space within the shoe. In cases where the existing built in insole cannot be removed, adding more thickness from the insole can reduce the available space for your feet.

When dealing with removable insoles, you have the flexibility to insert various insoles. However, it's important to note that these insoles come in different thicknesses and lengths, affecting the space they occupy. The greater the thickness and length of the orthotic, the more room it will require. 

Extra depth shoes are especially helpful and allow room for insoles in various thicknesses.

Moreover, shoes with narrower shapes naturally provide less space to begin with. In such cases, it’s best to opt for ¾ insoles that take up less space.