Classic fit versus regular fit, as Burberry uses the words
Burberry uses two fit words across its knitwear and states them plainly. The cashmere crewneck is described as cut to a classic fit and Burberry adds the guidance that it fits true to size and that you should take your normal size. Other styles in the same range, such as the men's Check Trim wool sweater, are described as regular fit with identical true-to-size guidance. Both are straight, unforced cuts rather than slim or oversized ones, and the difference between them is a little more or less room through the body and sleeve. The useful check is that the same cashmere crewneck appears as classic fit in some colourways and regular fit in others, so the fit word belongs to the piece you are looking at rather than to the style name as a whole.
The published length is the number worth comparing
The length figures Burberry publishes give a real basis for comparing styles. The men's cashmere crewneck is 68 cm in UK L. The men's fine-knit wool crewneck is listed at 68 cm in UK M on one colourway and 66.5 cm in UK M on another, which shows two different styles arriving at the same length from different letter sizes. The men's Check Trim wool sweater is 65.5 cm in UK M. On the women's side, the heavyweight wool-cashmere crewneck is 64 cm in UK S, the check-trim wool crewneck 61.5 cm in UK M and the lightweight cashmere crewneck 60 cm in UK S. The practical reading is that a men's crewneck in the equivalent letter size will usually be several centimetres longer than the women's version of the same garment.
Cashmere, wool and cotton-wool, and what changes
The fibre listing explains why two crewnecks of similar length feel different on. The men's cashmere crewneck is 98% cashmere with 1% elastane and 1% polyamide, and its trims are 97% cashmere — a specialist dry-clean piece with a soft, dense surface. The fine-knit wool crewnecks are 100% wool, with a trim blend that adds elastane, which is what gives the ribbed cuffs and hem their recovery. The women's heavyweight wool-cashmere style is a denser, warmer knit made in Italy. The women's cotton-wool and check-trim styles sit at the lighter end, and the published lengths track that: 52.5 cm for the midweight cotton-wool crewneck against 64 cm for the heavyweight wool-cashmere. Heavier yarns hold a straight line longer; lighter ones follow the body closer.
UK letter sizes, men's and women's, and care
Burberry sizes its knitwear in UK letters, and the men's and women's ranges are separate blocks rather than one chart with a shift. Burberry's own answer to sizing questions is that the size chart sits on each product page, and the model notes give a second reference point: the men's cashmere crewneck is shown on a model at 184 cm wearing UK L, while the men's fine-knit wool crewneck is shown on a model at 186 cm wearing UK M. Care is consistent across the cashmere and wool pieces — specialist dry clean — with the wool crewnecks made in Italy and the check-trim and cotton-wool styles imported. Because the length is published per size, it is the single figure that answers most fit questions before anything else has to be asked.