Vintage Sizing vs Modern Sizing: Buying Secondhand That Fits

There is no law that says what a size 10 is. In the United States there never has been a rule that manufacturers are obliged to follow: the old voluntary standard for womenswear was withdrawn decades ago, an industry body still publishes suggested measurement tables, and any brand remains free to ignore them. A size label is therefore a brand's opinion about who it wants its clothes to fit, recorded at a particular moment in that brand's history.

That is inconvenient when you buy new. It becomes a real problem when you buy secondhand, because the garment in front of you may be carrying an opinion held by a company that no longer exists, from a decade that drafted its patterns differently. The fix is not a conversion chart. It is a habit, and it takes about ten minutes to set up once.

Which numbers on a label are measurements and which are marketing

Not every size is equally fictional. It helps to know which category the number in front of you belongs to.

• Nominally real measurements. Men's trouser waist and inseam, men's dress shirt neck and sleeve, and hat sizes started life as inches. They are the most useful numbers on any label, which is not the same as saying they are accurate — plenty of modern trousers labelled W34 measure generously at the waistband, and a good number of older ones measure short.
• Ranked codes with no unit. Women's numeric sizes, alpha sizes from XS to XXL, and most children's sizes are positions on a scale, not quantities. Nothing about a 6 is six of anything. Two brands can place the same body at a 4 and a 10 without either being wrong, because there is nothing for them to be wrong about.
• Ages used as sizes. Children's sizing by age is the weakest signal in the whole system. It describes an average child of that age as one manufacturer imagined them, and children are famously not average. If you are buying in kids and baby, chest and length in inches beat the age on the tag every time.
• Shoe numbers. A shoe size describes a last — the wooden or plastic form the shoe was built around — more than it describes a foot. Two pairs marked 9 from different makers can differ in length and differ far more in width and volume.

The direction older sizes drift, and why nobody can give you a formula

The general pattern is well established and easy to state: over the second half of the twentieth century and into this one, the body measurements attached to a given size number grew. A number that once described a smaller set of measurements came to describe a larger set. So a vintage garment labelled with a particular number will usually correspond to a smaller number on a modern rack.

What you will also see, constantly, is somebody turning that pattern into arithmetic — subtract this many sizes and you have your answer. Do not trust it. The drift did not happen at one rate, at one time, across all brands. A mid-century dress, a 1980s catalogue blouse and a 1990s mall-brand top can each sit at a different distance from today's equivalent. Any single conversion figure is an average of a set of numbers that were never consistent to begin with.

There is a second problem with conversion thinking, and it matters more. The number changed, but so did the shape.

Cut changed as much as the number did

When you try on an older garment and it feels wrong in a way you cannot name, it is usually not the size. It is the pattern underneath it. A few of the differences you will meet most often in vintage and in older pieces filed under womenswear:

• Rise. Trouser and skirt rise has moved up and down repeatedly. A high-rise vintage pair sits at the natural waist, which is narrower than the hip a low-rise pair sits on — so the waist measurement that fits you in one is not the one that fits you in the other.
• Armhole and shoulder. Older tailored pieces often have a higher, tighter armhole and a narrower shoulder than a modern casual equivalent. A high armhole actually gives you more arm movement in a jacket, but it feels restrictive if you are used to a dropped shoulder.
• Ease. Ease is the difference between the garment and the body inside it. The fashionable amount of ease swings hard between decades, so two garments with identical chest measurements can read as fitted and as oversized.
• Shrink-to-fit denim. Some older jeans were sold unwashed, labelled at their pre-shrink measurement. A pair like that has almost certainly been washed by now, so the tag describes a garment that no longer exists. Measure it.

Build a reference from the clothes you already own

This is the habit that replaces all of the above. Go through your wardrobe and pick out the pieces that genuinely fit you best — not the ones you like most, the ones that fit. One t-shirt or knit top. One button shirt. One pair of trousers or jeans. A dress or a jacket if you buy them. Three or four garments is plenty.

Measure each of them across the points that decide fit for that garment type, and keep the numbers somewhere you will have them when you are looking at a listing on your phone. From then on you are never comparing a garment to your body, which is difficult, and never comparing it to a size label, which is meaningless. You are comparing one object to another object.

The mechanics of taking those measurements — where pit to pit is actually taken from, why a flat number is half a circumference, which measurement decides fit for each kind of garment — are worth getting right, and we set them out step by step in how to read flat-lay measurements on a clothing listing.

One warning about the reference garments themselves. If a piece has been altered — taken in at the side seams, hemmed, sleeves shortened — it is a reference for the altered version, not for the size on its tag. That is fine, and arguably better, as long as you know.

Fabric decides how much slack you need

Two garments with the same measurements can still fit differently because of what they are made of, and the composition tag is usually easier to trust than the size tag.

Rigid fabrics — a hundred per cent cotton denim, a tightly woven twill, a stiff canvas — give you what the tape measure says and nothing more. There is no recovery either: if it is tight across the seat, it will be tight across the seat forever, and forcing it puts the strain onto seams that are decades old.

A small proportion of elastane changes the arithmetic entirely, which is why so much modern denim carries it. Knitwear moves differently again: a knit stretches under load and relaxes back, so it tolerates a garment measurement below your body measurement in a way a woven never will. It also means a knit can be stretched out of shape by the person who owned it before you, which is a condition question rather than a sizing one.

When a listing does not give you the numbers

Ask. Everything in our menswear and womenswear is a single physical object sitting on a shelf here, not a line in a catalogue that can be re-ordered in another size, so taking a tape to it is a two-minute job. A measurement we can actually take is worth more to both of us than a return.

And judge the fabric while you are asking. A garment can be exactly the right size and still be a poor buy if the knit is thinned at the elbows or the denim is worn through behind the pocket — the faults that decide that are covered in judging used clothing condition from photos.

The part that makes secondhand easier, not harder

All of this sounds like a tax on buying used clothing. It is closer to the opposite. A new garment is a promise: it has not shrunk yet, it has not relaxed yet, it has not been washed, and the label is the only information you have about any of that.

A pre-owned garment has already done its shrinking, already relaxed where it is going to relax, and can be measured as it will be when it arrives. Everything we sell is pre-owned — including pieces that still have their tags — and every one of them is photographed exactly as it is. The label on it is a historical document. The tape measure is the fact.