How To Measure Insoles

Let’s ask the million dollar question first- why would it be important to measure your insoles in the first place?

No matter how sure you are of your shoe size, it is still pretty important to know what your insole size is, specifically when buying sandals or shoes from a brand unknown to you as well as to achieve an optimum fit in the future. These measurements are a also a key factor when shopping for off-the-shelf orthopaedic insoles.

Your numerical shoe size, whether it be in a US, UK or French size is based on the length of your foot, it is measured from the heel to the tip of the longest toe. This measurement doesn’t factor in width - so first you need to determine the width of your shoe fit.

Most reputable online retailers provide in-depth measurements and measuring tools for consumers who shop online- a savvy way of ensuring your shoes fit to the tee, would be to not only focus on the actual size you think you wear but to actually fit to the measurement of the sole of your foot.

There are various reasons why you might consider buying or using an insole- perhaps for a medically diagnosed condition such as Morton's’ Neuroma or for something less dramatic but also featuring heavily on the pain scale like Plantar Fasciitis or even for a condition that is more biomechanical in nature like over-supination or overpronation. Sportsmen and hikers also use performance-based insoles.

Knowing your measurements will assist you in buying the right insole that fits both your shoe and your needs.

There is one key factor to consider when measuring for an insole for sports performance: the heel to ball ratio. Often, feet could be the same length, but could require completely different sized inserts based on the distance between the ball under the big toe and the end of the heel- this ratio is of particular importance when searching for sports insoles or half insoles.

Here’s how you measure your insole

1. Take your favorite, best fitting pair of shoes

2. Using a flexible tape measure or a ribbon that you can mark on

3. Push the end that is marked with the 0 right into the tip of the toe on the inside of your shoe

4. Laying the tape flat, walk it all the way to the inside of the heel, laying it flat against the bottom of the shoe

5. This measurement is your true insole length

6. Measure in cm- if the size ends up between half sizes, round up to the nearest ½ size, eg. 18.25cm will be rounded up to 18.5cm

Here is a great sizing guide to determine the length of your foot and what your true shoe size is.

How to measure your heel to ball ratio

1. Stand on a flat surface on a clean piece of paper with your heel touching and not overlapping the edge of the page. Mark the heel out holding the pen perpendicular to the foot- now extend the line, using a ruler from the curved end of the heel to the outside of the foot

2. Get the person helping you to mark the spot where the ball of your foot touches the paper-

   • if you have normal arches- this will be quite obvious to spot as it will be the part that touches the paper in front of the gap that your arch will make.

   • If you have fallen arches, this ball position should be identified from the top of the foot but finding the ball position with your fingers, then touching the paper in exactly the same position and marking that off.

3. Using a measuring tape, the person measuring you will measure the length from the ball position to where you extended the heel line.

4. This measurement is your heel to ball ratio- repeat on the other foot.

Most off-the-shelf insoles are made somewhat longer than you need, so you can trim off the excess, the measurements above are purely for a more specialized performance insole or for a custom corrective one.