Two sizing systems, one catalog. This page says which applies to what.

Letter sizes, and how deep each one runs

The letter on a top is the same letter across the whole catalog, but not every line reaches both ends of the range. This table counts what we actually hold.

Waist and inseam, on the pants that use them

Work pants and bibs are sized the honest way, by waist and inseam. Scrub pants use letters, so the inseam rides on the letter.

Measure a garment, not yourself

• Lay a top flat and measure across the chest, one inch below the armhole. Double it.
• Lay pants flat and measure the waist across. Double it, then measure the inseam from crotch to hem.
• Compare those numbers with the size chart on the product page, not with the size you usually buy.

Between two sizes

Knit tops: take the smaller, knit gives. Woven shirts: take the larger, woven does not. Canvas pants: take the smaller waist, canvas softens by half a size.