The centimetre number is a strap length, and 44 is not one
Gucci defines the belt size as the distance to the third hole. On a Double G reference it runs from the outer edge of the buckle; on a standard buckle it runs from the beginning of the strap. A size 90 therefore does not equal a 90 cm body waist. Both published ladders start well above zero, at 65 cm on the women's chart and 75 cm on the men's, so a two-digit figure of 44 sits 21 cm below the smaller floor and cannot be read as centimetres. Read as inches, 44 in converts to 111.8 cm at 2.54 cm per inch, which lands inside both ladders yet on none of the stamps in the published sample of 75, 80, 90 and 100 cm. Read as a trouser size it never becomes a belt length without a measurement. The reliable comparison is another belt that fits: lay it flat, find the hole you use and measure from the buckle edge to that point.
Women's and men's ladders read differently, and the US column is not the jeans column
Gucci publishes a women's belt ladder from 65 cm to 120 cm and a men's ladder from 75 cm to 120 cm, then adds two numbered columns that do not move at the same rate. On the women's rows the US column climbs from 25 at 75 cm to 30 at 100 cm, five steps across 25 cm, so one US size is 5 cm of strap. The jeans column on the same rows climbs from 24 to 34, ten steps across the same 25 cm, so a jeans size is 2.5 cm. On the men's rows the two columns coincide: 26 at 75 cm and 36 at 100 cm in both, again 2.5 cm per step. The same 90 cm strap therefore reads US 28 on the women's chart and US 32 on the men's, with jeans 30 against jeans 32. Quote the centimetre stamp and the ladder it belongs to, never a bare US number.
Canvas changes wear, not the size ladder
GG Supreme canvas is a coated material with leather trim. It stays flatter than soft leather and can mark first at the edge, especially where the keeper loop bends it. The printed surface may hide small scuffs better than smooth leather while showing edge wear more clearly. None of that changes the measured strap length. Ask for close photographs of the edge, the buckle, the keeper and the holes. A flat front image can show the monogram but not whether the strap is beginning to separate at the trim.
Width and buckle size are separate decisions
Gucci prints strap widths in inches. The common wide canvas strap is 1.5 in, about 3.8 cm; the metric shorthand calls it a 4 cm belt. The larger interlocking-G buckle dominates a narrow strap and reads more like a plate on a wide one. Compare the buckle width with the strap in a single photograph rather than judging the hardware from a cropped front view. Note the hardware finish too: gold-tone, palladium-tone and other finishes appear on different references and do not indicate a different size.
The four-part canvas-belt check
Ask for the full strap in frame, a tape from the buckle edge to the third hole, the number of holes and the width across the webbing. Add the interior stamp and the colour of the edge trim. If the belt is being compared with one already worn, match the same hole. For an on-waist fit, the placement changes the useful circumference and may point to a different row than a hip fit. That is a fit decision to measure, not a reason to guess one size down.