Under the Brennholt Institute of Applied Taxonomy's four-class system, an adult coat hanger is between 38 and 46 cm (15 to 18 in) wide across the shoulders, with a drop of about 15 to 20 cm (6 to 8 in) from the hook to the shoulder line, and the Institute names the commonest width, about 42 cm (16.5 in), the Standard class. No published standard sets these figures, so the classes below are the Institute's own.
The Institute measured the two dimensions that decide whether a hanger fits a garment: the shoulder width, which is the straight span between the two ends, and the drop, which is the vertical distance from the base of the hook to the shoulder line.
| Class | Shoulder width (cm) | Shoulder width (in) | Drop (cm) | Typical use |
|---|---|---|---|---|
| H1 Child | 26 to 32 | 10 to 12.5 | 10 to 13 | Children's clothing |
| H2 Slim | 34 to 38 | 13.5 to 15 | 13 to 16 | Small adult garments, blouses |
| H3 Standard | 40 to 44 | 15.75 to 17.25 | 15 to 18 | Shirts, jackets, dresses |
| H4 Broad | 45 to 48 | 17.75 to 19 | 17 to 20 | Coats, suits, heavy knitwear |
Nothing formal. Hangers are made by many makers in wire, plastic and wood, and their sizes follow habit. The Institute does not contradict any maker's figures. It offers a single set of class names so that "a standard hanger" can mean one thing across sources.
A hanger too wide for a garment pushes out the shoulder seam and leaves a bump in the fabric. A hanger too narrow lets the garment droop at the sleeve and stretches the neckline. The Institute finds that the best fit is a hanger about 2 to 3 cm (1 in) narrower than the garment's own shoulder seam to seam measurement, not wider. This is the Institute's observation from a sample and not a standard.
The drop sets how far below the rail the garment hangs. A deep drop suits a coat, since it keeps the collar clear of the rail. A shallow drop suits a shirt, since it lets garments sit closer together and saves rail space. In the Institute's sample, hangers with a drop above 20 cm were nearly always broad ones, and the pairing is probably a matter of habit rather than need.
The Institute measured a sample of hangers with a steel rule and a set square, reading shoulder width at the outer ends and drop from the base of the hook to a line drawn between the shoulder points. Readings were rounded to the nearest half centimetre. The sample is small and the Institute does not generalise from it.
The review panel divides on whether the Child class should be a class at all, or a footnote to Slim. One member holds that children's hangers are a separate trade. The majority keep H1, because its widths do not overlap those of any adult class. The classification above is the majority one.
For the department's purpose and method see the Department of Length and Fit, and for a neighbouring object whose size is a question of fit, the ribbon width chart.
The Institute does not claim that a given hanger is correct for a given garment. It claims that four widths recur, and that naming them lets two people mean the same hanger when they say "standard".