Shoe Size Converter

Incorrect footwear sizing is the primary cause of returns in e-commerce, leading to logistical waste and consumer frustration. This tool mitigates sizing errors by cross-referencing international standards (US, UK, EU) with precise foot length measurements in centimeters. Unlike generic charts, this application addresses the inconsistency of manufacturer molds.

Shoe sizing is not a linear scale; it relies on distinct systems like the Brannock device (US) or the Paris point (EU). For instance, a 1 size difference in the EU system corresponds to 6.67 mm, whereas a US half-size increment represents approximately 4.23 mm. This discrepancy creates alignment issues when converting directly between regions without a control unit (CM).

The integrated Brand Fit Logic compensates for known deviations in lasting. Athletic brands often run narrower or shorter than leather dress shoes. By applying a mathematical offset to the base conversion, this tool provides a recommended purchase size rather than a raw conversion, reducing the probability of poor fit.

The calculation relies on the Last Length rather than just the foot length. The standard conversion from centimeters to EU sizing uses the Paris Point system:

Where C represents the toe-box allowance (typically 1.5 to 2 points). For US sizes, the zero-point differs between men, women, and children. The Brand Fit Logic applies a scalar offset:

If a brand runs "Small", the offset is positive (e.g., +0.5), suggesting a larger size is needed to accommodate the foot.