Oval, round, square, oblong, heart, diamond and triangle. Classification comes down to one ratio (length ÷ width) and two width comparisons (forehead vs jaw, cheekbones vs both). Each encyclopedia page pairs with topic pages — hairstyles, glasses, beard, brows, collars.
Take the five-question self-quiz, the ruler method, or let the FaceLab tool classify from a photo with the exact ratio reported.