Sneakers Size Calculator

How to calculate sneakers size

Sneakers sizing starts with foot length, measured from the back of the heel to the tip of the longest toe while standing, in the socks you plan to wear. Measure both feet and use the longer one, because most people have one foot slightly longer than the other. The calculator compares your foot length with broad adult ranges and returns the matching row as a starting size, then adjusts it for use, width and arch.

Width and arch then shape the final choice, because a sneaker that is the right length can still pinch across the forefoot or press the arch. The calculator asks for narrow, regular, wide or extra wide, and for low, medium or high arch, so its notes change with your answers.

Do not choose sneakers size from foot length alone

Foot length alone misses the parts of a sneaker that fail first. Width decides whether the forefoot can spread, arch type decides whether the insole feels supportive or pressing, and use decides whether half a size of extra room is needed for swelling during a run. If your foot is wide, the right fix is a wide fit in the correct length, not a longer size that leaves the heel loose.

Heel drop matters for comfort rather than for size, but it changes how the shoe feels under your heel and how your calf works. A low drop feels flatter, a mid drop suits most road running, and a high drop gives more heel cushioning. For the general background on shoe fit, see how shoes should fit.

General sneakers size chart

The chart below gives broad adult foot length ranges in inches and centimetres, with US women's, US men's, UK and EU columns. Treat these as starting ranges, not as brand sizes.

How width changes the choice

A narrow foot slides inside a regular width sneaker, which causes heel slip and a sloppy feel, while a wide foot pinches inside a regular width sneaker, which causes sore spots and numb toes. Width is measured across the ball of the foot, the widest part, and the upper should lie flat across the forefoot without bulging outward over the midsole at the sides.

Do not try to fix a narrow foot by sizing down, because that takes length away from the toes as well as width from the forefoot. Do not try to fix a wide foot by sizing up, because that adds length you do not need and leaves the heel loose. Pick the width that matches your foot, then pick the size that matches your foot length. For more on width labels, see wide versus standard shoe width.

How arch type and heel drop change the fit

Arch type changes which insole shape will feel comfortable. A low arch usually feels better with a flatter insole and light support, a medium arch feels best with gentle support that meets the arch without pressing it, and a high arch usually wants a contoured insole that fills the space under the arch. If the arch support feels like a hard lump, the insole shape does not match your arch.

Heel drop changes how the shoe feels under your heel and how your calf works, so it is worth choosing deliberately. A low drop of 0 to 4 mm feels flatter, a mid drop of 5 to 8 mm is the most common range for road running, and a high drop of 9 to 12 mm gives more heel cushioning.

The running rule: half a size up

Feet swell during a run as blood flow increases and warmth builds, and they slide forward a little with each landing. A pair that fits snugly at the start of a run can feel tight by the end, and toes that clear the front at the start can hit it after a few miles. That is why the common running rule is to go half a size up from your everyday sneaker size, keeping about a thumb width of space in front of your longest toe.

Apply the rule from your everyday sneaker size, not from a dress shoe or a different brand, because each brand grades differently. The calculator applies the rule for you when you choose running use, moving one row up the chart from your everyday size.

Signs sneakers are too small

• Your longest toe touches or presses the front of the shoe when you stand or walk.
• Your toes feel squeezed together and cannot spread or wiggle freely.
• The upper bulges outward over the midsole at the sides of the forefoot.
• Your toenails hurt or bruise after a run or a long walk, especially downhill.

Signs sneakers are too large

• Your heel lifts and slips up and down with every step, even when the laces are snug.
• Your foot slides forward inside the shoe when you walk downhill or stop quickly.
• There is loose fabric across the forefoot and your foot moves side to side.
• You need to lace the shoe very tightly to feel held, and the top of your foot still feels loose.

How to choose sneakers size online

Shopping online removes the fitting room, so measurements matter even more. Take fresh foot length and width measurements, use the calculator for a starting size, then open the brand chart and compare your foot length in centimetres with the brand column, not just the size label. If the brand also lists width, compare that too, especially if your foot is wide or narrow.

Read the fit notes as well as the chart. A brand that describes a model as running narrow has already built a close forefoot into its sizes, so sizing down on top of that can leave you with sneakers that pinch at the sides and press your toes together. Check the return policy too, and consider ordering two sizes when returns are free. For a fuller method, see how to choose shoe size online.

Common sneakers sizing mistakes

• Choosing by your usual size label without checking the brand chart.
• Measuring while sitting, which leaves the foot shorter than it is when you stand.
• Using foot length alone and ignoring width, arch type and use.
• Sizing up to fix a narrow forefoot, which adds length and leaves the heel loose.
• Copying a size from an everyday sneaker to a running sneaker without adding half a size.