International Size Converter Pro - IT, EU, US, UK, JP
Convert clothing and shoe sizes between IT, EU, US, UK, and JP systems using ISO 8559-1:2017 tables. Brand-specific notes for H&M, Zara, and Nike included.
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Frequently Asked Questions
How do sizes convert from Italian to American?
Italian clothing sizes (IT) are typically 2 numbers higher than the corresponding EU size. To convert IT→US, correspondence depends on category: for an IT top, 42 corresponds to M US; 46 corresponds to L US. For shoes, conversion is 1:1 and US corresponds approximately to IT -1. This converter uses ISO 8559-1:2017 tables.
What's the difference between EU size and Italian size?
Italian clothing sizes are 2 numbers higher than European sizes for tops and bottoms: IT 40 = EU 38, IT 42 = EU 40. Shoe sizes match (continental shared system). The historical difference comes from different body measurement systems.
How do sizes vary between brands like H&M, Zara and Nike?
Every brand has its own production tolerances that can differ from the ISO standard table. H&M tends to cut small sizes. Zara follows the EU standard fairly closely. Nike for shoes, US sizing may be half a size lower than the IT/EU system. Selecting the brand in this converter will give you specific notes on variations.
What does "UK size" mean and how does it compare to EU?
UK sizes for women's clothing are about 4 numbers smaller than EU sizes: EU 38 = UK 10, EU 40 = UK 12. For shoes, UK is about 1 size smaller than EU: EU 40 = UK 6.5 women, EU 42 = UK 8 men. The UK system differs from the US system: UK 8 and US 8 for shoes do not match the same measurement.
How does Japanese sizing work?
Japanese clothing system (JP) uses odd numbers: JP 7 ≈ EU 36 ≈ IT 38, JP 9 ≈ EU 38 ≈ IT 40. For shoes, the Japanese system uses foot length in centimeters (e.g., JP 24 = 24 cm) with good correlation to EU sizes. The Japanese market tends to prefer slim cuts over European standards.
Are S/M/L sizes always the same numbers?
No, sizes S/M/L do not have a universal fixed correspondence: they depend on the category and brand. According to ISO 8559-1:2017, for an Italian women's top: S = 38–40, M = 42–44, L = 46–48. Fast fashion brands often interpret differently. Always consult the specific body measurement table of the brand for online purchases.
How is it used?
- Select Main Category
Choose between tops/shirt/dress, bottoms/pants, women's or men's shoes. Each category has a separate ISO table for maximum accuracy.
- Indicate system and starting size
Choose your size system (IT, EU, US, UK, JP) and enter the size. For tops, enter S/M/L or numbers (e.g., 42); for shoes, enter the number (e.g., 42 or 42.5).
- Optional brand for specific notes
If you know the shoe head is from H&M, Zara or Nike, you can select the brand: the converter shows specific notes on shoe variations. Leave "No Brand" for the ISO standard table.
- Read results on all systems
The result shows the equivalent size in IT, EU, US, UK and JP. If the size is not on the table, you will receive a "not on table" message.
International size converter: how does the ISO table work
International Clothing Size Converter Pro translates clothing and shoe measurements between five reference systems: Italian (IT), European (EU), American (US), British (UK) and Japanese (JP). The tables are based on the ISO 8559-1:2017 standard for body measurements and ISO 3635:1981 for garment size labeling - the most up-to-date international standards in the fashion industry.
Sizing systems vary historically by country: Italy uses a numerical system (36, 38, 40...) with tops starting at 36 for smaller sizes. The European system tends to be two numbers lower than the Italian one for clothing (IT 42 = EU 40). Americans use both letters (XS, S, M, L) and numbers for women's clothes. British sizing is even more different. Japan uses odd numbers (5, 7, 9...) for clothing.
For shoes, the European (EU) and Italian (IT) systems coincide - both use the size in "Paris points" (units of 6.67 mm). The American system differs from the EU by about 1-1.5 numbers depending on the type. The British is about 0.5-1 number less than the American. The Japanese measures directly the length of the foot in centimeters.
Brand notes (H&M, Zara, Nike) are classified as MEDIUM and updated periodically: reflecting the declared shoe trends by brands themselves and consolidated customer feedback. They do not replace the brand's measurement chart, available on every official site. For major purchases, always measure chest, waist, and hips and compare with the specific size guide.
This tool is designed for multi-brand retailers, personal shoppers, fashion buyers, and online consumers buying from international e-commerce sites. All calculations occur in the browser - no data is sent to external servers.
Practical example
- Buyer with size IT 42 for a women's t-shirt wants to buy on a US-based ecommerce site.
- Select Category: Top / Shirt / Suit - System: IT - Size: 42
- Currency Converter Returns: IT 42 = EU 40 = US $ = UK 12 = JP ¥11
- If the head is H&M, the brand note warns: "H&M tends to cut down on smalls - consider a size up.
Vocabulary Dictionary
- Fit Options
- Italian sizing system for clothing that uses even numbers (36, 38, 40, 42...). For women's tops, the size IT is typically two sizes larger than the EU size. For shoes, the IT system coincides with the EU system (Paris points).
- Fit EU (European)
- European system used mainly in France, Germany, Spain and the rest of the EU. For clothing sizes are two points lower than Italian (EU 38 = IT 40). For shoes, EU and IT coincide with the Paris point system (1 point = 6.67mm).
- US Size (American)
- American clothing system using letters (XS, S, M, L, XL) or even numbers (0, 2, 4...). For shoes, use distinct decimal numbers for men and women, with an approximate correspondence of IT/EU-1 for women and -0.5 for men.
- UK Size (British)
- British clothing system that starts from lower sizes compared to the EU (UK 8 = EU 36). For shoes, UKs are about 0.5-1 size less than US (UK 5 = EU 38 women). Note: UK and US shoe sizes do not match the same number.
- Japan Size
- Japanese clothing system that uses odd numbers (5, 7, 9, 11...). For shoes, use the length of the foot in centimeters (e.g. JP 24 = 24 cm foot length), with excellent direct correspondence to EU sizes for footwear.
- International Organization for Standardization ISO/IEC standard
- International ISO standard for body measurements in clothing. Defines standard measurement points (chest, waist, hips, leg length) and corresponding sizes. Used as a basis by all major fashion sizing systems in Europe, USA, and Japan.
- Size Guide/Measurement Chart
- Body measurement chart specific to each brand, available on every e-commerce site. Provides exact measurements of chest, waist, and hips corresponding to every size of the brand. More precise than any general conversion table for online purchases.
Do you need a custom analysis?
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