Shoe size (adult) is based on an old measure known as the “barleycorn.” England’s king Edward II originated shoe sizes in 1324. He decreed that three barleycorns (grains of barley), placed end to end, equaled one inch. The longest normal foot measured 39 barleycorns, or 13 inches, and was size 13.
Smaller sizes were graded down from this number, each by a third of an inch. Shoe sizes vary in different countries. The same shoe, for instance, may be marked 4 1/2, 6, 25, etc., depending on that country’s custom for shoe size measurement. Old measurements may no longer be accurate: adults’ feet, like children’s, change with age and activity.
In the United States, shoe fittings are usually made with a tool called the Brannock Device, made since 1927 by a company of the same name in Syracuse, NY. The person being fitted should sit and keep his or her socks on. If the person doing the fitting has a fitting stool, he or she puts the measuring device on the inclined ramp of the stool, otherwise on the floor. Either way, the measuring device must be moved about until the leg is perpendicular to the foot.
The fitter first measures the distance from the heel to the ball of the foot, taken as the outermost point of the bone. Call this the arch length. Then the distance from the heel to the longest toe is measured. In doing so the sock is drawn against the ends of the toes so that only two layers of cloth (at heel and toe) are included in the measurement, and the toes are gently pressed down. Call this measurement the toe length.
If the arch length (in the markings on the device, not in inches!) is the same as the toe length, this is the basis of the size. If the toe length is greater, it is the correct size. If the arch length is half a size larger than the toe length, the arch length is the correct size.
Having the size, the width can now be determined. Some judgment is called for. Feet with very high insteps may need a width one size larger than the measuring device indicates, while if the foot is thin it’s considered good procedure to apply a bit of pressure with the bar used to measure width, to see if the foot compresses to a smaller width. In some countries width is determined by measuring the circumference of the foot at the ball joint with a tape measure.
Widths are designated by letters. The average man takes a C or D width, but shoes are made up to E. Now the whole procedure must be repeated with the other foot. Always insist on having both feet measured. The rule of thumb to live by when buying a pair of shoes is that there should be a thumb’s width between the tip of the longest toe in your foot and the end of the shoe. The first, second or third toes are often the landmarks because they are usually the longest toes in your foot.
Always buy a pair of shoes that fit the bigger foot. The reason for this is that you can place an over the counter insole in the larger one to either take up some of the room or prevent foot slippage. Never force your foot into a shoe that is too small or too tight. Wearing ill-fitting shoes can cause foot, ankle, knee and low back problems.
Shoes that do not fit properly can throw your balance off and make you walk funny. If the shoe is too narrow you can develop ingrown toe nails, corns on the top and side of your toes and irritate the skin resulting in blister formation.
Content for this question contributed by Tina Book, resident of Feeding Hills, Agawam, Massachusetts, USA