Ordering a military uniform across the Atlantic requires understanding size conventions. Here is the practical guide.
Quick answer. UK and US men's jacket sizes are roughly equivalent: UK 40 equals US 40 for most makers, both referring to the chest measurement in inches. European sizes are different: UK 40 equals Euro 50 for most makers. Trouser sizes use waist measurement in inches in both UK and US (W32, W34). Shoe sizes are different: UK 9 equals US 10 for most men's styles. Head sizes for hats are in inches (UK and US) or centimetres (Europe); UK 7 1/4 equals 58cm. Always provide full body measurements for bespoke orders rather than relying on size numbers.
Chest and jacket size
The jacket chest size refers to the chest measurement in inches. UK and US both use the same inches, so UK 40 equals US 40. European sizes add 10 to this: UK 40 equals Euro 50. Italian sizes use a slightly different scale (UK 40 equals Italian 50 usually). Note that drop (the difference between chest and waist) varies by maker: a slim fit jacket has 7 or 8 inch drop, a classic fit has 6 inch drop. For historical uniforms, drop varies by period: Napoleonic coats are slim fitted (7 inch drop); Victorian frock coats are classic (6 inch drop).
Trousers
Trouser waist sizes are given in inches in both UK and US: W32, W34, W36 refer to the waistband inner measurement. European waist sizes add about 14: W32 equals Euro 46. Inside leg (inseam) is also in inches: L30, L32, L34. European inside leg uses centimetres: L32 equals 81 cm. For historical breeches and pantaloons, the fit is tighter than modern trousers: measure 2 inches smaller at the waist for breeches to allow the proper fit.
Shirt sizes
Shirt sizes typically use the collar measurement in inches: UK 15.5, US 15.5, Euro 39 or 40. The collar size is the circumference around the base of the neck. Sleeve length varies by region: UK and Euro shirts typically have a shorter sleeve than US shirts for the same chest size. For historical shirts (linen pullover style) the collar measurement is less important because the collar is adjustable with ties or buttons. Historical shirts typically fit by chest and sleeve.
Footwear
Shoe sizes are where UK and US diverge most. For most men's shoes: UK 7 equals US 8, UK 8 equals US 9, UK 9 equals US 10. European sizes are different again: UK 9 equals Euro 43. For boots in particular, the specific maker's size chart matters more than the general conversion. Width varies: US shoes often come in width options (B, D, E, EE) while UK shoes often come in F, G, H. For bespoke boots, provide the inch measurement of your foot length and width.
Headwear
Hat sizes are in inches of circumference (UK and US) or centimetres (Europe). UK 7 1/4 equals 58cm. Historical headwear sizes depend on the item: a shako is relatively adjustable with internal padding, a cocked bicorne has limited adjustment, a busby or bearskin is quite specific. For hats in general, measure your head circumference just above the ears and above the eyebrows, holding the tape measure firmly but not tightly. Provide the inch or centimetre measurement to the maker.
Bespoke orders across the Atlantic
For a bespoke uniform ordered from a different country, provide full body measurements rather than relying on size numbers. The important measurements: chest at nipple, waist at natural waist, hip, back shoulder width, back length (from neck to natural waist), outside sleeve (from shoulder to wrist with arm slightly bent), inside sleeve, inside leg, outside leg, neck circumference, head circumference. These numbers are standard internationally. Provide them in both inches and centimetres if possible to avoid any conversion confusion.
Common questions
Is a UK jacket size the same as a US jacket size?
For most makers, yes. UK 40 equals US 40, both referring to the chest in inches.
How does European sizing differ?
European sizes add 10 to UK and US sizes. UK 40 equals Euro 50. European trousers add 14 to UK and US sizes: W32 equals Euro 46.
How do UK and US shoe sizes compare?
UK is one size smaller than US for most men's styles. UK 9 equals US 10.
What is the drop in a jacket size?
The difference between chest and waist. A classic fit has 6 inch drop; a slim fit has 7 to 8 inch drop. Historical Napoleonic coats are slim fitted; Victorian frock coats are classic.
Should I rely on size numbers for bespoke?
No. Always provide full body measurements in inches or centimetres. Size numbers vary by maker.