Shoe size conversion

This shoe size conversion calculator helps estimate equivalent shoe sizes across major international sizing systems using standardized foot measurement relationships.

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Shoe size conversion helps you understand and compare shoe sizes from different international sizing systems. Because there isn’t a single global standard, shoe size labels can vary widely across regions, brands, and gender categories. This tool and guide help you convert between major sizing systems — including U.S., UK, EU, Japan/Mexico, China, and more — based primarily on foot length.

Note: Shoe size is influenced by many factors beyond foot length — such as shoe shape, brand, and foot width — so conversions serve as useful reference points rather than exact fits.

How shoe size is calculated

Different countries use distinct measurement traditions to determine shoe sizes. Many calculators estimate shoe size based on foot length in inches or centimeters using standard formulae.

Common sizing systems

• U.S. and Canada – Shoe sizes differ for men and women (L is foot length in inches).
  • Women’s = ≈ (3 × L) − 21
  • Men’s = ≈ (3 × L) − 22
  • Big kid’s shoe size ≈ (3 × L) – 22¾
  • Little kid’s shoe size ≈ (3 × L) – 9¾
• UK and India – Based on a barleycorn measurement system (L is foot length in inches):
  • Adult shoe size ≈ (3 × L) – 23
  • big kid’s shoe size ≈ (3 × L) – 23¾
  • little kid’s shoe size ≈ (3 × L) – 10¾
• European (EU) – Uses a different scale tied to foot length in centimeters (L is foot length in centimeters):
  • EU size ≈ (1.5 × L) + 2
• Japan and Mexico – Typically based directly on foot length in centimeters (L is foot length in centimeters).
  • Shoe size = L
• China – Another centimeters-based system with a different offset (L is foot length in centimeters).
  • Shoe size = 2L – 10

These formulae give a consistent baseline for converting between systems, though individual brands may vary.

Shoe size conversion charts

Below are typical conversion tables used to compare shoe sizes across major sizing systems. These values are approximate and should be used as a reference.

Adult women’s shoe sizes

Adult men’s shoe sizes

Infant and toddler shoe sizes (Age 0–4)

Kid’s shoe sizes (Age 5–12)

How to measure your foot

Accurate measurement improves conversion accuracy:

1. Place a sheet of paper on the floor against a wall.
2. Stand with your heel against the wall and your foot flat on the paper.
3. Mark the tip of your longest toe and measure the distance from the wall.
   • Do this for both feet — use the longer measurement.
4. Convert the measurement to inches or centimeters to use in the conversion formula or chart.

Understanding fit beyond size

Keep in mind:

• Shoe sizes provide a starting point, but fit can vary by brand, model, and even shoe style.
• Width, arch shape, and personal comfort preferences may require sizing adjustments.
• Always refer to brand-specific size charts when available.

Foot measurement devices and systems

Foot measurement systems use a combination of measuring devices and standardized sizing schemes to translate physical foot dimensions into shoe sizes. Over time, several tools and systems have been developed, each with different goals—ranging from retail convenience to international standardization.

Brannock device

The Brannock device is the most widely used foot-measuring instrument in retail shoe stores, particularly in the United States.

What it measures

• Foot length
• Foot width
• Heel-to-ball length (arch length)

How it works

The device uses a sliding heel cup and scale markings to determine the appropriate shoe size. Unlike systems based solely on overall foot length, the Brannock Device accounts for arch position, which can affect shoe fit even when two people have the same foot length.

Usage

• Common in shoe stores for men, women, and children
• Provides separate size scales for gender and age groups
• Width measurements are indicated using lettered widths (e.g., D, EE)

Limitations

• Results still depend on shoe design and brand
• Measures foot dimensions, not comfort preferences or shoe volume

Ritz stick

The Ritz stick is an older, simpler measuring tool that predates the Brannock Device and was commonly used in shoe retail environments. Because it captures fewer dimensions of the foot, the Ritz stick has largely fallen out of use.

Characteristics

• Measures foot length only
• Typically constructed as a flat, straight ruler
• Lacks arch or width measurement capability

Mondopoint system (ISO standard)

Mondopoint is an internationally standardized shoe sizing system defined under ISO 9407.

Core principles

• Based on actual foot dimensions
• Uses millimeters as the unit
• Incorporates both:
  • Foot length
  • Foot width

Format

Mondopoint sizes are typically written as:

Length / Width
Example: 260 / 100

This means:

• 260 mm foot length
• 100 mm foot width

Where it’s used

• Military footwear
• Ski boots
• Safety shoes
• Performance and specialty footwear

Advantages

• Highly precise
• Eliminates ambiguity between men’s and women’s sizes
• Reduces international conversion errors

Limitations

• Less familiar to general consumers
• Limited adoption in everyday fashion footwear

Paris point system (European)

The Paris point system is the basis of European (EU) shoe sizing.

• 1 Paris point = ⅔ cm
• Shoe sizes increase in uniform increments
• Uses foot length plus an allowance for toe movement

This system does not distinguish between men’s and women’s sizes, relying instead on numeric scaling.

Barleycorn system (UK and US Origins)

The barleycorn is a traditional unit of length equal to ⅓ inch.

UK system

• Shoe size increments = 1 barleycorn
• Adult sizes start from a fixed reference point

US system

• Derived from the UK system
• Different offsets for:
  • Men
  • Women
  • Children

Because of these offsets, US sizes are not a direct measurement of foot length.

Why multiple systems exist

Different systems reflect:

• Historical measurement practices
• Regional manufacturing standards
• Retail convenience
• Precision vs simplicity trade-offs

As a result, no single system dominates globally, making shoe size conversion tools essential.