Generally speaking, there should be about one finger's width of space between your longest toe and the end of the shoe. Another way to check this is to slip a finger between the heel of your foot and the heel of your shoe. There should be just enough space for your finger to fit nice and snugly.
Signs that your shoes are too small
In properly fitting shoes, your toes should be facing forward with enough space to move. Meanwhile, shoes that are too small will feel uncomfortably tight. You'll likely feel your toes touching the ends of your shoes and may get blisters on the backs of your heels.
Corns and calluses are foot deformities that are often caused when you wear shoes that are too tight, through friction from your toes constantly rubbing in a pair of shoes with reduced toe box volume. Aside from the pain and aching, the cramped atmosphere can form painful and unsightly corns and bunions.
There should be about half an inch between the end of your longest toe and the front of the shoe. If you have small hands, this is about the size of the tip of your index finger. If you have large hands, it's about the size of the tip of your pinky finger. For many people the big toe is the longest.
Snug shoes
For example, when it comes to leather shoes, you should choose the pair that's on the snug side. While it may seem more comfortable to get a pair with some extra room because dress shoes start out stiff, this will actually add to your discomfort over time as they relax and stretch.
While most shoes will stretch and mold to fit your feet over time, many can be manually stretched. Leather shoes are easiest to stretch, but most fabrics and materials can also be stretched.
A loose fit could put you at risk for injury. If you are between sizes, sizing down is a better option in this situation. It is always better to go half a size up for running shoes or trainers. Vigorous exercise will increase the blood supply to the feet and cause them to swell.
Properly fitting shoes stay in place as you move, but if the shoes are too big, you will almost certainly have painful blisters by the end of the day. Other painful effects of wearing shoes that are too big include: Corns and calluses: caused by excessive pressure on the toes.
Shoes will typically stretch all on their own as you wear them. Leather shoes, whether it be men's dress shoes or women's heels, will fit over time.
Buying a sneaker that is slightly larger than your foot allows for better circulation which minimizes swelling. If one foot is slightly larger than the other go for the bigger size and always consider the kind of socks you plan to wear with your shoes.
As a rule of thumb (or toe), you should have about 3/8″ to 1/2″ of room from the tip of your longest toe to the end of the shoe. Your big toe is not automatically your longest toe. Pick the shoes that match your foot shape.
The middle toe joint will bend up and if you have your foot in a tight shoe, it will rub up against the shoe surface and cause pain. In addition, the muscles that attach to the toes will continue to weaken if the foot stays in this abnormal position.
When your foot bends to take a step in a new shoe, your heels should slip slightly. 1/8” movement is normal but can feel like much more. Loose slipping in the heels will not cause blisters when broken in gradually, but wearing shoes that are too small and tight will cause friction and then blister.
A wide toe-spread is a clear visual sign your feet are most likely in proper healthy, functional condition. Especially if the big toe isn't folded inwards (towards 2nd toe) but points forward in a straight line from the heel (hallux angle). A wide toe-spread, means a bigger thus better base of support.
If you have one foot longer than the other, the difference between them is likely to be less than 1 cm. So the chances are that your longer foot won't require footwear in a larger shoe size than the other. The same can be said of feet that are different widths.
If your shoe is too tight, you may have blisters, numbness and general discomfort; to avoid this, many experts recommend buying a running shoe half a size larger. According to Runner's World, “You may think you know your size, but it's best to get your feet measured each time you buy new shoes.
A half size in shoes is only 1/8 of an inch in added length. Shoes size can vary for many reasons, from sports injuries to weight gain and age. It's not uncommon to go up a half size if your feet or arch height begins to become more flat overtime.
Measuring Foot Length
It is advisable to undertake this foot measuring exercise in the evening, as feet swell during the day, so your feet will be at the biggest by the evening (better a slightly big shoe which can take an insole, than a shoe that is too tight!).
Shoes that are on the tighter side are likely to rub, and since this friction can cause blisters, it's best to have a bit of wiggle room. The ball of your foot should fit comfortably in the widest part of the shoe, and at the heel make sure that you have some room for slight heel slippage.
Shoes that are too tight or provide too little support put ongoing pressure on your feet, ankles, shins and calves, and other joints. Over time, that pressure can lead to pain, dysfunction, and injury. Your shoes also affect the way you walk.
Typically shoes loosen up naturally as you wear them from place to place, but that entire process could take weeks of tiptoeing around with crunched toes and blooming blisters. But walking in shoes that pinch is something you can totally avoid.
First, you may have the wrong size or style of shoe. Some newer styles of shoes have a tight or pointy toe box and this can cause the toes to be close together and there may actually be irritation of the skin on adjacent toes.