How to Trim and Cut Shoe Insoles

Learning how to trim and cut shoe insoles correctly is important for a perfect fit. While trimming insoles isn’t hard, it can be intimidating the first time!

If you trim them too short, there’s nothing you can do to lengthen them again. You can also end up cutting them incorrectly and having the arch support in the wrong place.

Thankfully, it’s quite easy to do if you know the right way. In this article, we’ll explain how to trim new insoles to fit inside your favorite pair of shoes perfectly.

Why Trim a Shoe Insole?

Most over-the-counter, full-length insoles are designed to be trimmed before use, as they’re made to fit a range of shoe sizes.

For example, if you wear a size 8 shoe, you’ll need to get an insole that’s in the 8 to 10 size range. To get a comfortable fit, you’ll need to trim the oversized insole to fit properly within your shoe.

With that being said, both shoe and insole sizes can vary slightly. You may find that where a certain sized insole fits like a glove in one shoe, it may be tight and restricting in another shoe.

For this reason, we recommend you don’t use the same insole across multiple pairs of shoes.

Trimming your insoles lets you customize the fit for a specific shoe. We recommend buying multiple pairs of insoles so you can trim one for each different shoe.

What Do You Trim An Insole With?

Insoles are often made from highly durable material, and to trim them you’ll need a sharp pair of scissors. Make sure they aren’t blunt, as using sharp scissors will help you get a clean cut instead of a jagged one!

You’ll also need a sharpie or a pen to make the outline, and the original insert that you’ll be replacing with the new trimmed insert.

Steps to Trim and Insert

Here’s how to trim and cut shoe insoles the right way, so they fit perfectly into your selected shoe.

1. Remove the Insole From Your Shoe

Fortunately, most shoes have insoles that aren’t glued in, making them easy to replace.

To trim the insoles to the right size, remove the original insole from your pair of shoes.

However, if the shoes don’t allow you to remove the insoles, you may want to slip the new insole on top of the original insert of the shoe untrimmed.

This lets you gauge how much space—depth—is left in the shoe once you add the new insole to it.

If the shoe has plenty of depth remaining—in other words, can accommodate the new insole comfortably without constricting your foot—then you can get some recycled paper and insert it into the shoe.

Then, using a pen or sharpie, trace the outline of the original insole onto the paper. This may be a little tricky as you will have to stick the pen inside the shoe as best as you can.

Next, cut out the traced insole. This will be used as your “original” insoles when you trim the new pair.

2. Use an Old Insole to Get the Right Size

Place the original insole on top of the new insole, making sure to line up the edge of the heel and both the inside and outside edges of insoles.

Depending on the brand of insole and the type of support it provides, it could have an anatomical heel design or extra cushioning.

By lining up the heels of both insoles, it prevents unnecessary trimming of the heel that could reduce the insoles effectiveness.

You really only want to cut the insole in the forefoot, where there’s less cushioning or technology in the insole.

3. Trace an Outline on the New Insole

Once you have aligned the insoles use the sharpie—or pen—to trace around the original insole at any points where your new insole overlaps.

The traced line is going to be your guideline when you trim the insole. Don’t worry about drawing directly onto your clean new insole—nobody will see it once it’s inside your shoe!

4. Double Check Your Outline

Before you start trimming your insoles, double-check your outline with the aligned insoles. This will prevent you from trimming too much off the insole.

A good rule of thumb is to trim just a little at a time. You can always trim them down further if you don’t cut enough off the first time, but there’s no way you can make them bigger after you’ve trimmed them too much.

5. Cut It Down to Size

Trim the insole along the line you’ve just marked with your sharp pair of scissors. Your insole should look like a mirror image of the insole that you’re replacing.

6. Put It Back and Test

Place the insole into your shoe, using your hand to smooth it out and make sure that it lies flat with no buckling or curling up along the sides.

If your insole is still slightly too long or slightly too wide, remove it and trim a little more off until you get the perfect fit.