Accessories Size Guides
Watches, hats, belts, bracelets and glasses — sized from a simple measurement, with US, UK and EU equivalents.
Watch Size Calculator
Your wrist measurement tells you the watch case diameter, strap length and lug width that will look and fit right.
Open tool →Hat Size Calculator
Measure around your head and convert it to a US/UK fitted hat size, EU centimetres and S/M/L.
Open tool →Belt Size Calculator
Your belt size isn't your waist size — it's usually two inches larger. Enter your trouser waist to get it right.
Open tool →Bracelet Size Calculator
Measure your wrist and add the right amount of room for a snug, comfortable or loose bracelet fit.
Open tool →Glasses & Frame Sizes
Frame width, lens diameter and bridge width — how to read the three numbers on your glasses.
Open tool →Glove Size Guides
Glove size by hand circumference, with type guides for golf, ski, cycling, boxing and more.
Open tool →Hat sizes by head circumference
Belt sizes by waist
Watch sizes by wrist circumference
Once you know your frame width, Otra's fashion-forward sunglasses (worn by Kylie Jenner, Hailey Bieber) pack flat and ship globally.
Shop Otra Eyewear →