Sunglasses for your face shape: the one rule that works, and the ones that do not

Every sunglasses face-shape guide reduces to one rule: choose a frame whose dominant line contrasts the dominant line of your face. A round or oval face is softened by an angular frame; a square or angular face is softened by a rounder one. That rule works and it is the whole of the advice. What the guides usually leave out is that width matters more than shape. A frame the wrong width, more than about ten millimetres wider or narrower than your face, looks wrong on any face shape, and a frame the right width looks acceptable on most. Identify your shape, then measure your width, and let the width decide.

The rule, and why it works

A frame draws a line across the middle of your face. If that line repeats what is already there, it emphasises it: a round frame on a round face makes the roundness the thing you notice. If it contrasts, it balances: a straight-browed rectangle on a round face gives the eye an edge to rest on.

That is all any face-shape chart is doing. The six shapes below are six ways of applying it.

The six shapes

Oval. Forehead slightly wider than the chin, cheekbones the widest point, gently rounded jaw. The most forgiving shape. Almost any frame works; a rectangle adds structure, a round frame adds softness, and neither goes wrong.

Round. Width and length close to equal, soft jaw, full cheeks. The rule says angular: rectangular, square or a flat-browed frame. Avoid round and small frames, which repeat the curve.

Square. Strong jaw, wide forehead, width and length close to equal. The rule says soft: round, oval or a frame with a curved bottom edge. A rectangle with sharp corners doubles the angle; a rectangle with softened corners can work.

Heart. Wide forehead, narrow chin. Frames that are wider at the bottom or have a light, thin brow balance it. Avoid heavy top-bars that add to the forehead.

Diamond. Narrow forehead and chin, cheekbones the widest point. Frames with a defined brow line or a slight cat-eye lift draw the eye up. Rectangles work well.

Oblong. Longer than wide, straight cheek line. Frames with more height than width, or a low bridge, shorten the face. Avoid narrow, shallow frames.

Where a flat-browed rectangle fits

Our T01 is a rectangular frame with a flat brow line and a base that tapers toward the nose. By the rule:

The face shape guide on this site draws all six.

Why width matters more

Here is what the charts do not say. A frame of the right shape and the wrong width looks wrong. Too wide, and it slides and looks borrowed. Too narrow, and it pinches at the temples and looks small. A frame of the wrong shape and the right width usually looks fine.

Frame width, hinge to hinge, should be within about 10mm of the width of your face across the cheekbones. Our T01 is 140mm, which suits roughly 130 to 150mm faces. Below about 125mm it looks oversized whatever your face shape. Our measurements post shows how to measure in thirty seconds with a ruler.

How to identify your shape

Pull your hair back, look straight into a mirror, and trace the outline of your face with your eye. Ask two questions:

1. Is it longer than it is wide? If clearly yes, oval or oblong. If about equal, round or square.
2. Is the jaw soft or angular? Soft: round or oval. Angular: square. Narrow chin with wide forehead: heart. Narrow chin and forehead with wide cheekbones: diamond.

Ten seconds, and it does not need to be exact; the shapes shade into each other and the rule still applies.

Frequently asked questions