Shoe Fitting Fundamentals

Fundamentals of fit

Running Shoes

Running shoes are primarily designed for moving in a relatively linear direction over distance, therefore the fit of a running shoe needs to perform two main functions:

  1. Stabilise the foot when it is moving forwards in the sagittal plane (the plane of movement forwards and backwards of the body), helping to avoid any twisting from this straight forward path.
  2. Allow the foot to adapt to the ground and the environment as these factors change throughout the course of a run.

As the first point applies at any distance this principle applies to any running shoe, in practice this means that the shoe should grip the entire width of the foot securely, but not too restrictively; a bit like a reassuring hug all around the sides of your foot. The heel should sit securely, without excessive pressure from the shoe’s heel collar on the Achilles tendon. Some people insist on a concrete-like heel fit; however in reality this is rarely possible and a tiny amount of heel slip is probable and shouldn’t be dwelled upon too much as this can usually be improved with certain lacing techniques and sock selection.

The second point needs to be considered when selecting your size, as the distance you will be using the shoes for, the type of running and the ambient temperature/pressure will all affect which size will be optimum for you. Generally this judgement comes with experience, so if you can’t make it in-store then we would advise speaking to an experienced running club member or friend who may be able to help guide you in the right direction. As a rough guide if you are running shorter distances (less than 5-6 miles in any single run) then you should aim for around 8mm of extra space if your foot is a UK9.5 or larger or an extra 5mm if you are below a UK9.5; some much smaller feet may get away with slightly less space, but the key message here is if you run less than 5-6 miles then aim for small gap between your furthest toe and the end of the shoe. If you run between 6 to 15 miles then add an extra 3mm to the above fitting and if you intend on using the shoes for longer runs (above 15 miles in any one run) then we normally find that 20mm for the average man and 15mm for the average woman is adequate.

Other considerations

  • If you are running in climates that are hotter and/or more humid then you should allow slightly more space in the length of the shoes.
  • If you have a body mass index (BMI) which is higher than average then you should allow a little more space, conversely if you are lighter than average then you can afford to have the shoes a little tighter.


So the perfect running shoe fit remains elusive as ever, but the key thing to remember is that your running shoes should always fit nice and securely around the mid-foot and heel all the way up to the “knuckles” of the toes allowing for expansion room at the toes. Irrespective of the distance you are running, you should always be able to wiggle your toes, but the space you have free at the tips of the toes will depend on the factors discussed above. As a very rough rule of thumb, aim to go one size larger in your running shoes than your everyday shoes and you shouldn’t go too far wrong.

Court shoes

Court shoes include: tennis, netball, squash and badminton shoes; all of which are designed to offer maximum stability and comfort when you are moving in multiple directions. As stability is the main consideration with court shoes, the fit of these shoes should reflect this. So the key thing here is for the shoes to be as close fitting as possible, whilst retaining a level of comfort that will allow you to play for extended periods of time. We recommend that you choose a size in court shoes that matches your everyday shoes or if you are happy with a closer fit then aim for a half size smaller than your everyday shoes.

Other considerations

Again your weight and foot-size will affect the size you should select; heavier players will find that their feet expand more, as there will be greater relative forces exerted through the foot during games. One unique factor that can affect your size selection with court shoes is your playing style; if you are light on your feet and use subtle movements then foot expansion will be less; if you are heavy footed and focus on powerful movements; then your foot will be likely to expand more during games.

If you intend on wearing your court shoes for everyday or casual use, which will shorten the life of the shoes considerably, please bear in mind that a court shoe fitted correctly for the sport it is intended for will not be very comfortable when worn casually for extended periods of time; conversely a court shoe that fits comfortably for everyday/casual use will not perform as well on court. We mention this point here as we find that a wide range of customers prefer the look of court shoes when buying trainers for everyday use.


In terms of length, your toes should be close to touching the end of the shoe, we normally find that a gap between the end of your longest toe and the end of the shoe of 2-3mm should be ideal. Again the main reason for this is that a smaller shoe will offer more support around the foot and therefore you will have better stability and support, as foot expansion doesn’t occur as much when playing court sports as it does when you run, most people can get away with this smaller expansion gap.

Walking Shoes

Walking shoes are arguably more difficult to fit than running shoes as you are moving more slowly and have less adrenaline in your bloodstream; you will be more sensitive to any discomfort; thankfully foot expansion is less prominent when walking, so this takes some of the difficulty out of fitting walking shoes. The important fitting factors with walking shoes are similar to those of running shoes, so aim for a snug fit around the sides of the foot whilst allowing for some expansion room in the toes.

Other considerations

A key consideration with walking shoes is the type of sock you will choose to wear; as the variation in thickness and density of walking socks is greater than any other socks. So it is wise to take this into account when choosing your size. Also the type of walking you will be doing can affect your choice of size as country walking shoes that will be used when traversing will require a closer fit around the mid-foot than a fitness walking shoe used for walking on pavements; as with all shoes your body weight and foot size relationship will also play a part in obtaining the ideal fit.


In terms of length you should aim to have about 6-8mm of space in the toes, for foot expansion, bearing in mind that your feet will not swell a lot (in normal conditions) until distances of over 5-6 miles so you can afford less space if you are intending on only using the shoes for shorter walks. A secure fit around the circumference of the mid-foot is essential if you intend on using the shoes on rugged terrain; or traversing. A comfortable, yet snug fit around the mid-foot is ideal if you are only walking on flat firm surfaces.