Can I switch between metric and US measurements?

Yes. The setting lives in your account and applies everywhere - ingredient lists, instructions, and the steps read aloud in Live Cooking.

Conversions are deliberately cook-friendly rather than literal. 200°C is shown as 400°F because no oven dial has 392 on it, and small masses stay in grams because 3 g rounded to ounces is "0 oz".

There is a fuller explanation, with the conversions themselves, on our cooking conversions page.