Fit and measurement glossary

These are the definitions ShirtMath uses everywhere: in the measuring guides, in the catalogue, and in the scanner. A figure means the same thing wherever you meet it on this site. Terms run roughly top to bottom, shirts first, then trousers, then the vocabulary of sizing itself.

What is pit to pit?

Pit to pit is the flat chest measurement of a shirt. Lay the shirt flat, measure straight across 1 inch below the armholes, seam to seam. It is a half measurement, so double it for the garment's chest circumference. Brand size charts and ShirtMath both quote the flat figure, not the doubled one, and the pit to pit guide shows where the tape sits.

What is chest (flat)?

Chest, flat, is the same number as pit to pit; the two names are interchangeable on this site. Flat means the garment lies on a table with no stretch applied to it. A Gildan G500 Medium publishes a 20.0" flat chest, and a Next Level 3600 Medium publishes 20.5". Those two shirts carry the same letter and are half an inch apart before tolerance is counted.

What is body length (HPS to hem)?

Body length, HPS to hem: from the highest point of the shoulder seam straight down to the bottom hem. HPS stands for highest point of shoulder, the place where the shoulder seam meets the neckline. Unisex Medium tees in our dataset publish 29.0"; the garment-dyed Comfort Colors C4017 Medium publishes 29.5", the longest of them. Some brands measure from the centre back neck instead, which is a different starting point and a different number, so check which one a chart means before you compare.

What is shoulder seam to seam?

Shoulder, seam to seam: across the back of the flat shirt, from the outer edge of one shoulder seam to the outer edge of the other. On a drop-shoulder or boxy cut the seam sits below the shoulder bone, so the figure is wider than the wearer's shoulders and reads large next to a set-in shoulder. Many blank manufacturers do not publish it at all.

What is sleeve length?

On a T-shirt, sleeve length runs from the shoulder seam down the outside of the sleeve to the sleeve opening. On a dress shirt it usually runs from the centre back neck, across the shoulder and down to the cuff, which is a far longer number for the same garment. Two charts using the same words can therefore differ by inches. The sleeve length guide sets out both conventions.

What is hem width (sweep)?

Hem width, also called sweep, is the flat measurement straight across the bottom hem. Read against the chest figure it tells you the shape of the body: equal numbers mean a straight tube, a wider hem means an A-line, a narrower hem means a taper. It is the measurement that decides whether a shirt hangs clean over the waistband or flares over it.

What is the bicep measurement?

Bicep is the flat width of the sleeve, measured straight across at its widest point just below the armhole seam. Like the chest it is a half measurement. It is one of the two readings ShirtMath's scanner is least confident about, and a field it will leave blank rather than guess at.

What is sleeve opening?

Sleeve opening is the flat width across the very end of the sleeve, at the hem. It sets how close the sleeve sits to the arm and separates a fitted sleeve from a boxy one. It is the other reading the scanner treats as unreliable, because the edge is short, often curls, and hides its own seam.

What is neck opening?

Neck opening is measured flat across the inside of the collar, seam to seam. On a T-shirt that is a width, not a collar size. Dress shirts quote the neck as a circumference instead, which is where a size such as 15.5 comes from; the dress shirt size chart works in those numbers.

What is inseam?

Inseam is the length of the inner leg seam, from the crotch join straight down to the leg opening. It is the second number in a trouser size written as 32x30, where 30 is the inseam in inches. Measuring it on a trouser you already own is more reliable than measuring your leg, and the inseam guide covers the method.

What is front rise?

Front rise runs from the top of the waistband down the front of the trouser to the crotch join. It decides where the garment sits on the body: a shorter rise sits lower on the hips, a longer rise sits nearer the natural waist. Two trousers with an identical waist and inseam can feel completely different if their rises differ by an inch.

What is the thigh measurement?

Thigh is the flat width across one leg, taken about an inch below the crotch join. Double it for the circumference of the leg at its widest point. It separates a slim leg from a relaxed one far more decisively than the waist number does.

What is hip or seat?

Hip, also called seat, is the flat width across the trouser at the fullest part of the seat. It is a half measurement, so double it for the circumference. Brands publish it rarely, which is one reason trouser fit is harder to compare across labels than shirt fit.

What is leg opening?

Leg opening is the flat width across the bottom hem of one leg. It is the single figure that tells you whether a trouser is tapered, straight or wide. Compare it with the thigh: a large gap means taper, a small gap means a straight leg.

What is outseam?

Outseam is the length down the outside of the leg, from the top of the waistband to the leg opening. It is close to the inseam plus the rise, though not exactly, because the seams curve. Shorts are usually specified by outseam rather than inseam. The trouser measuring guide shows both.

What is drop?

Drop is the difference between two measurements on the same garment, most often chest minus waist on a jacket or a suit. A six inch drop means the waist measures six inches less than the chest. Tailored clothing uses drop to describe how shaped the body is. On a T-shirt the useful version is chest minus hem width.

What is ease?

Ease is the difference between the garment measurement and the body measurement underneath it. A 40 inch chest inside a garment measuring 44 inches around has four inches of ease. Ease is what fit words are really describing, which means every fit preference is a preference about ease. The fit guide works through how much of it different shapes need.

What is grading?

Grading is the rule a brand uses to step a pattern from one size to the next. The Gildan G500 grades a flat 2.0" of chest at every step from S to XL. The Next Level 3600 does not: it steps 1.5" up to L, then 2.0" to XL, so the gap between the two styles closes as the sizes rise.

The bottom row is the reason this glossary exists. A ladies' G500L Medium publishes 17.5" against 20.0" to 20.5" for the unisex Mediums, a three inch gap on the same letter, and the same three inch gap repeats at L. Medium names a different garment depending on the cut. More styles are listed in the chest measurement dataset.

What is vanity sizing?

Vanity sizing is the practice of putting a smaller size label on a larger garment, so that a shopper reads a flattering number. It is one of several reasons the same letter names different garments at different brands; cut, block and grading account for the rest. The vanity sizing guide separates the effects, and what size am I in a different brand covers what to do about it.

What are points of measure?

Points of measure, often shortened to POM, are the named places on a garment that a factory or a size chart measures. Chest, body length, shoulder, sleeve length and hem width are the core five for a T-shirt. Two charts can use identical POM names and still disagree, because the names do not fix the method. That is why every definition here says where the tape starts and where it stops.

What is a flat measurement?

A flat measurement is taken with the garment lying flat and unstretched on a table, edge to edge. It equals half the circumference of the garment at that point. Body measurements, by contrast, are circumferences taken around a person. ShirtMath compares flat garment measurements to flat garment measurements and does not measure bodies, which is the whole argument in body measurement versus garment measurement.

What does relaxed fit mean?

Relaxed fit means the garment is cut with more ease than the same brand's regular block: wider through the chest, straighter through the waist, usually roomier in the sleeve. It is a comparative word, not a measurement, so a relaxed cut at one brand can be narrower than a regular cut at another. Nothing obliges a brand to say what it is relaxed compared with. The flat chest and hem width figures answer the question the label cannot.

What does slim fit mean?

Slim fit means less ease than the same brand's regular block, usually taken out at the waist and the sleeve rather than the chest. Like relaxed, it is a house word with no external referent. The Next Level 3600 is sold as a fitted tee and publishes 19.0" at S against 18.0" for a Gildan G500 S, so a fitted label does not guarantee a narrower chest.

What does regular fit mean?

Regular fit is a brand's default block, the shape its other fits are named against. It has no fixed measurement and no industry definition. Because it is defined internally, regular at two brands can differ by more than the gap between regular and slim inside one brand.

What does modern fit mean?

Modern fit usually sits between slim and regular, and appears most often on dress shirts and tailored jackets. It is a naming convention rather than a measured standard, and brands apply it inconsistently. Treat it as a hint about shape, then check the chest, waist and sleeve figures.

What is a tall cut?

A tall cut adds body length and sleeve length while keeping the width close to the standard size, and is normally labelled LT, XLT and upward. The number that matters is HPS to hem: compare the tall version of a style against its standard version and the added length is visible immediately. Width often moves a little too, so read the chest figure rather than assuming it is unchanged.

What does garment-dyed mean?

Garment-dyed means the shirt is sewn first and dyed afterwards, which produces the soft hand and slightly uneven colour those styles are bought for. Dyeing a finished garment shrinks it, and not evenly, so garment-dyed styles carry a wider manufacturing tolerance than piece-dyed ones. The Comfort Colors C4017 is garment-dyed and carries roughly 0.8" of tolerance where a standard style carries around 0.3".

Common questions about fit terms

Where do these terms get used?

Each definition here has a page behind it. Start with the measuring method, then the charts that quote these points, then the styles whose published numbers you can compare directly.