Shoe Size Calculator

A Shoe Size Calculator is a digital conversion tool that translates foot length into shoe sizes for different countries. The tool uses shoe size calculation formulas developed by shoe makers before mass production created the need for a global standard.

Shoe sizing has no single international system. The U.S., Canada, UK, India, EU, Japan, Mexico, and China each use different numbering. A size 9 in U.S. men's equals a size 8 in UK, a 42–43 in EU, and a 27 cm in Japan/Mexico. The calculator handles these conversions in one step.

A Shoe Size Calculator is a tool that converts a foot measurement into shoe sizes across multiple country standards. The calculator accepts foot length in inches, centimeters, or millimeters and applies country-specific formulas to produce matching sizes for the U.S., Canada, UK, India, EU, Japan, Mexico, and China.

The calculator works in 3 steps:

1. Enter foot length in inches or cm.
2. Select gender or age group.
3. Read the output shoe size for the chosen country.

The result returns the women's shoe size, men's shoe size, big kid's shoe size, or little kid's shoe size, depending on the input. Some calculators also display the equivalent in the Mondopoint system used in Russia, East Germany, Taiwan, South Korea, China, and Japan.

Wearing the right shoe size prevents 5 common foot problems: blisters, bunions, calluses, arch strain, and pinched nerves. Shoes that run too tight create pressure points. Shoes that run too loose cause friction.

There are 3 main reasons proper sizing matters:

• Comfort: a snug but not tight fit keeps feet pain-free during long hours of walking or standing.
• Health: properly fitting shoes support the foot's natural shape, reducing long-term damage to joints, tendons, and ligaments.
• Performance: athletic shoes need precise sizing for stability in running, training, and team sports.

Foot length, foot width, and foot shape all change with age. Feet often grow half a size larger by evening due to swelling, so an afternoon measurement gives the most reliable result.

To measure your foot, use a flat surface, paper, a pen, and a ruler or tape measure. The measurement must capture both foot length (heel to longest toe) and foot width (widest part of the ball of the foot).

Step-by-Step Guide to Measuring at Home

To measure foot length and foot width at home, follow these 6 steps:

1. Place a sheet of paper on a hard, flat floor against a wall.
2. Stand on the paper with your heel touching the wall.
3. Mark the tip of your longest toe with a pen held perpendicular to the paper.
4. Measure the distance from the wall edge to the mark in inches (in) and centimeters (cm).
5. Trace the widest part of your foot for foot width.
6. Repeat with the other foot, since most people have one foot slightly larger than the other.

Use the larger foot's measurement when checking the shoe size chart. Measure in the late afternoon, when feet reach their daily maximum.

Tools for Measurement: Tape Measure, Paper, and Foot Gauges

There are 4 common tools for foot measurement:

• Tape measure: gives length in inches, cm, and millimeters (mm); flexible enough to track foot width and the circumference of the ball of the foot.
• Paper and pen: traces foot outline for both length and width; works for adults and children.
• Brannock device: a metal foot gauge used in shoe stores that measures foot length, foot width, and arch length together.
• RITZ stick: a wooden slide ruler with men's and women's shoe sizes printed on it; preceded the Brannock device as the standard retail tool.

The Brannock device remains the most accurate retail option. The RITZ stick wooden slide ruler is older but still appears in some shops for quick conversions.

How to Measure Children's Feet

Children's feet grow fast, so measure them every 2–3 months. Use the same heel-to-toe method on paper, then add 0.5 inches (1.27 cm) of growing room when matching the result to a shoe size chart.

For infants and toddlers who cannot stand still, trace the foot while the child is seated and the foot is flat on the paper. Press gently at the heel and toes to capture the natural foot length.

Children's shoe sizes are split into 4 groupings: infants (0–9 months), toddlers (9 months–4 years), little kids (4–7 years), and big kids (7–12 years).

Shoe size conversion charts show matching sizes across the U.S., Canada (US/CA), the UK, India (UK/IN), the EU, Japan, Mexico (JP/MX), China (CN), and foot length in inches and cm. The chart format keeps women's shoe size, men's shoe size, and kids' shoe size separate because the same foot length maps to different numbers depending on gender and age.

Women's Shoe Size Conversion

Women's shoe sizes run from US 4 (foot length 8.3 in / 21.2 cm) to US 12 (foot length 11 in / 27.9 cm). Each US size adds approximately 1/3 inch (about 0.85 cm) of foot length.

Men's Shoe Size Conversion

Men's shoe sizes start at US 6 (9.3 in / 23.7 cm) and reach US 14 (12 in / 30.5 cm). UK sizes run 1 number smaller than US for the same foot length, so a US 9 equals a UK 8.

Children's Shoe Size Conversion

Children's shoe sizes are split into 4 age bands. The numbering restarts twice, first when toddlers transition into little kids around US size 10–11, and again at US size 1 (youth) when little kids transition into big kids.

International sizing systems differ in 3 main ways: the starting number, the size increment (half-point increments vs. whole-point increments), and the measurement unit (inches, cm, or millimeters). The U.S. and UK use half-point increments based on inches. The EU and China use whole-point increments based on centimeters.

Converting Between US, UK, and EU Sizes

US and UK sizes differ by approximately 1 full size for adults. A US women's 9 equals a UK 7, and a US men's 9 equals a UK 8. EU sizes use larger numbers: add 31 to a US men's size for a rough EU equivalent, or 32 for women's.

Direct conversions for 3 common adult sizes:

Regional Sizing: Australia (AU), UAE, and Korea

• Australian (AU) shoe sizes match either US or UK, depending on the brand. Women's AU sizes usually follow UK numbering. Men's AU sizes often follow UK as well, though athletic shoes imported from the U.S. keep US sizing.
• United Arab Emirates (UAE) shoe sizes follow the EU system. A US women's 8 is an EU 39, and the same EU 39 in UAE retailers like Steve Madden UAE.
• Korean (South Korea) shoe sizes use the Mondopoint system: the number equals foot length in millimeters. A foot length of 255 mm equals a Korean size 255, which matches a US men's 8 or US women's 8.5.

Converting Shoe Sizes to Inches and Centimeters (CM)

Foot length in inches converts to centimeters by multiplying by 2.54 (e.g., 10 in × 2.54 = 25.4 cm). Foot length in millimeters converts to centimeters by dividing by 10 (e.g., 254 mm ÷ 10 = 25.4 cm).

Quick reference for 3 common adult foot lengths:

• 9 in (22.9 cm) = US women's 6 / UK 4 / EU 36
• 10 in (25.4 cm) = US women's 9.5 / US men's 8 / UK 7 / EU 41
• 11 in (27.9 cm) = US women's 12 / US men's 11 / UK 10 / EU 44

Shoe size calculation formulas convert foot length directly into a country's shoe size number. The formulas below use L as foot length in inches (for US, CA, UK, IN) or centimeters (for EU, JP, MX, CN). The formulas come from calculator.net and other published shoe size conversion references.

The 3 main foot measurement systems are the Brannock device, the RITZ stick, and the Mondopoint system.

The Brannock device measures 3 dimensions at once: foot length (heel to longest toe), foot width (widest point at the ball of the foot), and arch length (heel to inside of the ball of the foot). The device pairs with the Brannock shoe size system, which outputs US shoe sizes primarily using:

The RITZ stick is a wooden slide rule that preceded the Brannock device as the standard retail tool. It carries men's and women's shoe sizes on one face and a length-to-width conversion chart on the opposite side.

The Mondopoint system measures foot length and foot width in millimeters and is used for ski boots, skates, and ballet shoes. The Mondopoint system is also the primary shoe sizing standard in Russia, East Germany, Taiwan, China, Japan, and South Korea. Mondopoint takes 3 measurements:

• Foot length: heel to longest toe, in millimeters.
• Foot width: across the first and fifth metatarsophalangeal joints.
• Perimeter: circumference of the foot around the ball, in millimeters.

The Mondopoint system accounts for the circumference of the ball of the foot and heel width, giving better fit accuracy than systems based on foot length alone.

Choose a shoe size based on the larger foot, since most people have one foot slightly bigger. Measure in the late afternoon when feet are at their daily maximum size. Wear the socks you plan to use with the new shoes during measurement.

There are 5 practical tips for accurate sizing:

1. Measure both feet and use the larger result.
2. Add 0.4 in (1 cm) of toe room for walking shoes.
3. Match length first, then check foot width for the right fit.
4. Try the shoe with normal socks, not bare feet.
5. Walk in the shoes for at least 2 minutes before deciding.

Shoe size varies across manufacturers because each uses a different shoe last (the wooden or plastic form used in production). A US 9 from one brand may fit differently from a US 9 from another.

What to Do if You Are Between Sizes

If your foot length falls between two sizes, round up to the larger size. The extra room prevents toe pressure and accommodates natural foot swelling during the day.

For athletic shoes used in soccer or climbing, round down for tighter dexterity. For everyday shoes worn 8+ hours, round up for comfort.

Finding the Right Fit for Wide Feet

For wide feet, look for shoes labeled with width designations such as D (standard men's), 2E (wide men's), B (standard women's), or D (wide women's). The width letter follows the size number: a US men's 10 D means standard width, while a US men's 10 2E means wide width.

If a brand does not offer wide widths, size up by half a point to gain extra room at the ball of the foot. Confirm foot width measurement, not just foot length, when sizing wide feet.