Square and Heart faces are among the pairs most commonly confused with each other, usually because one or two measurements land close together even though the overall proportions differ.
Square Face Shape
Square: Forehead, cheekbone, and jaw widths are nearly equal; face length is close to face width. A square face has a broad, angular forehead and a jaw with a defined, often 90-degree-adjacent corner at the hinge. Width stays consistent from temple to jaw rather than tapering, and the chin is flat or minimally curved rather than pointed.
Heart Face Shape
Heart: Forehead and cheekbones are noticeably wider than the jaw; chin comes to a visible point. A heart-shaped face widens at the forehead and temples, narrows through the cheekbones, and tapers to a pointed or narrow chin — the inverse proportion of a triangle shape. Many heart faces also have a slight widow's peak, which reinforces the forehead's visual width.
The Key Difference
The key difference: A square face has a jaw that "the defining feature — strong, straight, with a visible corner at the angle," while a heart face's jaw "tapers inward significantly compared to the forehead." That single measurement — jaw width relative to forehead and cheekbones — is usually the fastest way to tell the two apart when they're otherwise close.
Why It Matters for Styling
Why it matters for styling: Square faces are best served by soften the jaw's hard corner and add movement at the temples and chin, while heart faces need balance the forehead-to-chin taper by adding volume or width at the jawline and softening or minimizing width at the forehead and temples, which brings the upper and lower face into closer visual proportion — confirming which category you actually fall into before choosing a cut, frame, or beard style matters, since the two shapes' styling advice can point in different directions.