Hi
Given your wrist circumference, you could wear either a 38mm or 42mm Apple Watch. Which size looks best and which is the best option for you are matters of personal preference.
To compare the actual sizes of Apple Watch against your wrist:
- On your iPhone, open the Apple Store app:
- Go to: Shop (tab) > Apple Watch > Shop all Apple Watch > select any model > tap on the blue link for "Compare case sizes".
- Tap the 38mm and 42mm tabs to see the Apple Watch displayed at its actual size, for holding next to your wrist.
For all preconfigured combinations of Apple Watch and band, the product description in the Apple Online Store states the wrist circumference that the watch and band combination will fit. When checking sizes, keep in mind that 6 inches is around 152.4 mm.
For example:
- Apple Watch - Space Gray Aluminum Case with Gray Sport Band - Apple
- Band with 38mm case fits 130-200mm wrists.
- Band with 42mm case fits 140–210mm wrists.
Stated wrist sizes relate to the wrist circumference that the combination of band + case is designed to fit.
You may prefer to visit an Apple Store or Apple Reseller to try on different Apple Watch sizes before deciding which model to buy.