The short answer: the number on a pre-owned garment's tag is a starting point, not a verdict. Sizes shift between countries, between decades, and even between two labels in the same year, so the reliable way to buy is to convert the tag to a rough international equivalent, then confirm it against the garment's actual flat measurements. This guide gives you both: conversion charts for women's, men's and kids' clothing, and a repeatable method for checking fit before you buy.
Why pre-owned sizing is harder than it looks
Standard sizing has never been truly standard. There is no single legal definition of a US size 8 or a European 40, and brands are free to cut however they like. Add three more variables and the picture gets cloudier:
- Vanity sizing. Over several decades, many brands have labeled the same body measurements with progressively smaller numbers. A size 12 from an older garment can sit closer to a modern size 8 or 10.
- Country of origin. A jacket labeled 38 might be a European women's size, a UK men's chest measurement, or something else entirely, depending on where the label was made.
- Wear and care. Cotton relaxes, knitwear stretches or felts, and denim can shrink or fade. A garment that has been worn and washed for years may no longer match the size on its tag.
If you want the deeper story on why older labels run differently, our guide to vintage sizing covers it. This article is the practical companion: charts and a method you can use today.
Step one: know your own measurements
Before any chart is useful, you need your numbers. Use a soft tape measure over lightly fitted clothing and keep it snug but not tight.
- Bust or chest: around the fullest part, tape level across the back.
- Waist: around your natural waist, the narrowest point of your torso, usually just above the navel.
- Hip: around the fullest part of the hips and seat.
- Inseam: inside leg from crotch to the point where you want trousers to end.
- Shoulder width: seam to seam across the back, which matters most for blazers and coats.
Write them down in both inches and centimeters. Pre-owned listings often use one or the other, and having both ready saves you from doing math mid-checkout.
Women's clothing: approximate size conversion
These figures are approximate and meant to orient you. Brands differ, so treat any row as a range rather than an exact match.
| US | UK | DE / FR | IT | Letter | Bust (in) | Waist (in) | Hip (in) |
|---|---|---|---|---|---|---|---|
| 0 | 4 | 30 / 32 | 36 | XXS | 31 | 24 | 34 |
| 2 | 6 | 32 / 34 | 38 | XS | 32 | 25 | 35 |
| 4 | 8 | 34 / 36 | 40 | S | 34 | 27 | 37 |
| 6 | 10 | 36 / 38 | 42 | S/M | 35 | 28 | 38 |
| 8 | 12 | 38 / 40 | 44 | M | 36 | 29 | 39 |
| 10 | 14 | 40 / 42 | 46 | M/L | 38 | 31 | 41 |
| 12 | 16 | 42 / 44 | 48 | L | 40 | 33 | 43 |
| 14 | 18 | 44 / 46 | 50 | XL | 42 | 35 | 45 |
A few notes on reading it. French sizes run two numbers above the equivalent German size, which is why you see the pairs above (German first, French second). Japanese sizing typically runs smaller again, so a Japanese 9 is often closer to a US 4 to 6. And trousers and denim are frequently labeled by waist in inches (a 27 or 28), which is a separate system from dress sizing entirely.
Shoes
For women's shoes, a US 8 is roughly a UK 6, an EU 38 to 39, and a Japanese 25 cm. Pre-owned shoes also carry the wear pattern of a previous owner, so check the insole and heel wear in the photos, and when in doubt choose the half size that suits your foot's width.
Men's clothing: approximate size conversion
Men's tailoring is usually labeled by chest measurement in inches (UK and US) or a European number that is roughly the chest in centimeters divided by two.
| Letter | US / UK jacket | EU jacket | Chest (in) | Waist (in) | Neck (in) |
|---|---|---|---|---|---|
| XS | 34 | 44 | 34 | 28 | 14 |
| S | 36 | 46 | 36 | 30 | 14.5 |
| M | 38 / 40 | 48 / 50 | 38 to 40 | 32 to 33 | 15 to 15.5 |
| L | 42 | 52 | 42 | 35 | 16 |
| XL | 44 / 46 | 54 / 56 | 44 to 46 | 37 to 39 | 17 |
| XXL | 48 | 58 | 48 | 41 | 18 |
Two things trip people up most. First, a men's jacket often comes with a length designation: S (short), R (regular) or L (long). A 40R and a 40L share a chest but not a torso length. Second, dress shirts are sized by neck and sleeve length (for example 15.5/34), not by S, M or L, so measure your neck before you shop for them.
If you are new to buying menswear this way, our first-timer's guide to menswear walks through what to inspect beyond fit.
Trousers and denim
Men's trousers use waist by inseam, so a 32x32 means a 32-inch waist and 32-inch inseam. Remember that older and well-worn jeans may measure a little smaller or larger than the tag, which is why a flat waist measurement is worth asking about.
Kids' clothing: size by age, then by measurement
Children's sizing combines age labels with height and weight, and it varies more than adult sizing because children grow unevenly. As a rough guide, a size labeled 4T usually fits a child around 40 to 41 inches tall, 6 around 45 to 47 inches, and 8 around 50 to 52 inches. Always use height as your anchor, then check whether the brand runs slim or roomy.
Pre-owned kids' clothing is a smart place to be flexible: buying one size up gives room to grow, and soft, well-washed fabrics are often more comfortable than stiff new ones. Browse our kids' collection with a measured height in hand and you will rarely need to guess.
The five-minute method for confirming fit
Charts get you into the right neighborhood. This method gets you to the right front door.
- Convert the tag. Use the charts above to translate the label into your usual size system.
- Find the flat measurements. Look for pit-to-pit (chest width), waist, rise, inseam and shoulder-to-shoulder in the listing. If they are missing, ask.
- Compare to a garment you own. Lay your best-fitting similar piece flat, measure the same points, and compare. Doubling a flat chest measurement gives you the full circumference.
- Account for fabric. Stretch knits and blends forgive a size either way. Rigid wovens, raw denim and structured tailoring do not.
- Check the shoulders last. A tailor can adjust a waist or hem. Shoulders are the hardest part of a jacket to alter, so they are the one place to be strict.
Common mistakes to avoid
- Trusting the number over the measurements. A size 6 and a size 12 can be the same garment in different decades.
- Mixing up a waist size and a dress size. A 28 on jeans is inches. A 28 on a European dress would be unusual and worth a question.
- Ignoring fabric content. Linen and wool relax with wear. Cotton may shrink if it was washed hot. If you want help with care, see our guides to wool and denim.
- Forgetting plus and petite ranges. Specialist cuts have their own proportions. Our petite and plus-size guide covers how to shop them.
When a tailor is worth it
Pre-owned buying and tailoring are natural partners. Hemming trousers, taking in a waist, or shortening sleeves are inexpensive adjustments that can turn a nearly-right piece into a perfect one. As a rule of thumb, buy for the shoulders and the widest part of your body, and tailor everything else.
Finding your size at CENT'ANNII
Every piece in CENT'ANNII's curated edit is hand-inspected, and listings include the size on the tag so you can cross-reference the charts above. For shoppers who want to start with a confident fit, browse the women's collection, the men's collection, or the denim collection, and use your measurements as a filter. If something does not work, we offer a 30-day return window: email us to request a return, and we will send a label once it is approved.
Frequently asked questions
Is a US size 8 the same as a UK 8?
No. A US 8 generally corresponds to a UK 12 in women's clothing. The UK number is typically four higher than the US number.
How do I convert a European size to a US size?
For women's clothing, subtract roughly 30 from a German or Northern European size to estimate the US number (a German 38 is about a US 8; add two for the French equivalent, which would be a 40). Treat it as an estimate and confirm against measurements.
Why does a pre-owned garment fit differently from its tag?
Vanity sizing, washing, stretching and years of wear all change how a garment fits. Flat measurements tell you more than the label.
Which measurements matter most when shopping online?
For tops and jackets, chest width and shoulder width. For trousers and jeans, waist, rise and inseam. For dresses, bust, waist and length.
Should I size up or down on pre-owned clothing?
Go by measurements rather than a blanket rule. If a piece is a stretch knit, you have flexibility. If it is tailored or raw denim, stay close to your true size.
Are kids' sizes consistent between brands?
Not especially. Use your child's current height as the anchor and check the listing's measurements.
