It seems that the U.S. and the U.K. are separated by more than one wide ocean. When shopping in England, Northern Ireland, the Republic of Ireland, Scotland or Wales — or more likely shopping online — it's apparent that Americans label shoe sizes differently than in the U.K. (which is different again from the Continental Europe sizing system). Furthermore, the conversion guidelines for changing U.S. shoe sizes to U.K. shoe sizes are different for men's and women's shoes.

Converting U.S. to U.K. Shoe Sizes

In Great Britain and Ireland, women's shoe sizes run two numbers lower than American shoe sizes. For example, a U.S. size 8 is a U.K. size 6, and a U.S. size 7.5 is a U.K. size 5.5.

For men's shoes, the sizes run one number lower. Therefore, a U.S. size 9 is a U.K. size 8, and a U.S. size 9.5 is a U.K. 8.5.

How to Create a Template for Shoe Sizing

Any uncertainty about shoe size can be alleviated by making a template. With or without socks on, depending on the type of new footwear in mind, simply use a pencil to mark the tip of the longest toe and the back of the heel on a piece of plain paper. Alternatively, stand with heels against a wall with a flat ruler placed alongside the inside of the foot, taking care to use fractions of inches or centimeters. Measure the distance of the longest toe to heel in inches or centimeters to determine a shoe size using a conversion chart made for this purpose.

When to Create a Template for Shoe Sizing

Take foot measurements in the afternoon or evening, as feet tend to swell during the course of the day. Both feet should be measured, as there can be as much as a half or full size difference between them. Be aware that aging, weight gain or loss, air travel, exercise and pregnancy are some of the factors that naturally account for changes in shoe size over time.

Convert a Foot Measurement to Shoe Size

Measuring foot length does not account for width and instep, and the foot is three-dimensional, so any two-dimensional measuring tool can only approximate the best fit for an individual. Roughly speaking, shoe sizes increase by one size for each 1/8 to 1/4 inch in length. Should one foot measure differently than the other, which is quite common, use the larger size. If half sizes are not available, brands suggest opting for the larger size and using foam or gel sole inserts for a better fit.

Shoe Designer Differences

Even the finest handmade shoes are constructed on a shaped wooden or plastic mold, known as a last. Only the costliest custom-made shoes can be assembled on a personal last fitted precisely to the customer's feet. For online shoppers, an internet search will produce varied results in shoe conversion charts, as brands use somewhat different calibrations. Amazon UK highlights several of these brands. Also worth noting: The way in which men's sneakers (called trainers in the U.K.) are sized up can be slightly different from other types of men's footwear.