Most men guess their face shape and get it wrong, usually because they look at the whole head, hair included. Your face shape is the outline from the hairline to the chin, so pull your hair back and look straight into a mirror before you decide anything.

If the outline is not obvious, four measurements settle it. You need a soft tape measure, or a piece of string and a ruler. Use the same unit each time and take each measurement twice if a number looks odd.

1. Forehead: across the widest point, usually halfway between your eyebrows and hairline.
2. Cheekbones: across the face, just below the outer corners of your eyes.
3. Jaw: from the corner below one ear to the same point on the other side.
4. Length: from the centre of your hairline to the bottom of your chin.

Now compare. If the length is clearly bigger than every width, your face is long: oval if it narrows gently at the jaw, rectangle if it stays the same width all the way down. If the length and the widest width are close, your face is round or square, and the jaw decides which. When one width is clearly the biggest, that tells you the rest: widest cheekbones point to diamond, a widest forehead to heart, and a widest jaw to triangle.

Each shape has one feature that decides the cut: the widest part of the face, and whether the face is long or short for its width. The table gives you the short version; the sections below explain why each cut works.

Face shape	How to spot it	Best haircuts	Skip
Oval	Longer than wide, forehead a little wider than the jaw	Almost anything: French crop, short flow, crew cut	Heavy fringe that hides the forehead
Round	About as wide as long, full cheeks, soft jaw	High fades with height on top, quiffs, side parts	One-length buzz cut, blunt fringe
Square	Forehead, cheeks and jaw similar width, strong jaw	Crew cut, buzz cut, textured crop	Flat tops, jaw-length hair
Rectangle	Clearly long, even width all the way down	Fringes, side-swept styles, waves and curls	Tall quiffs, high skin fades
Diamond	Cheekbones widest, narrow forehead and chin	Fringes, textured crops, medium length	Very short sides with a tall top
Heart	Wide forehead narrowing to a small chin	Medium length, side parts, loose fringes	Big volume on top, slicked back
Triangle	Jaw is the widest part, narrower forehead	Volume on top: quiffs, wolf cuts, curly tops	Buzz cuts, very tight skin fades

A haircut cannot change your bone structure, but it changes the outline people see. Three simple rules sit behind every recommendation in the finder.

Height makes a face look longer. Volume on top, a quiff or a textured crop pushed upwards adds length to the outline. That helps round, square and triangle faces, and works against long ones.

Width at the sides makes a face look wider. Longer sides, waves and curls that sit out from the head, or hair tucked behind the ears all add width. That balances long and diamond faces, but makes a round face look fuller.

A fringe shortens the face. Hair that falls forward covers part of the forehead and pulls the eye down. It is one of the easiest fixes for a long face or a high hairline, and the reason oval faces should avoid very heavy fringes.

Once you know these three rules, you can judge any haircut photo yourself: ask where it adds height, where it adds width and how much forehead it shows.

Oval Face

The most balanced shape, so short, medium and textured styles all work. Pick by hair type and how long you want to spend styling. A French crop, a short flow or a classic crew cut are easy wins. The only real mistake is hiding the shape under a heavy fringe or very long, flat hair.

Round Face

Keep the sides short with a mid or high fade and leave length and texture on top, so the eye moves up rather than across. A side part or an angled quiff adds the corners a round face lacks. Avoid width at cheek level, one-length buzz cuts and a blunt fringe straight across the forehead.

Square Face

A strong jaw is an asset, so short, clean cuts suit you: a crew cut, a buzz cut or a textured crop. If the jaw feels too boxy, a little movement on top softens the corners. Skip flat tops, which repeat the square, and hair that ends right at the jaw.

Rectangle (Oblong) Face

Your goal is width, not height. A fringe shortens the forehead, and natural waves or curls add width at the sides. Keep the fade low or ask for a taper. Tall quiffs and very high skin fades make the face look longer still.

Diamond Face

Cheekbones are the widest point, so add fullness at the forehead and keep some length at the sides to soften them. A textured fringe or medium length tucked behind the ears balances the cheeks. Very short sides with a tall top make the cheekbones look even sharper.

Heart Face

Medium length at the sides and a loose, textured fringe work best, because they fill in around a narrower chin. A side part also works well. Big volume on top or hair slicked straight back makes the forehead look even wider.

Triangle Face

With a wide jaw, put the volume up top. A textured quiff, a wolf cut or a curly top balances the shape, and a beard kept short at the sides helps too. A buzz cut or a very tight skin fade makes the jaw the widest feature.

Face shape tells you where to add or remove volume. Hair type tells you how easily your hair will do it, and it is the reason the same cut looks different on two men with the same face.

Straight hair lies flat and shows every line of the cut. Ask for texture on top, point cutting rather than blunt ends, and use a matte paste or clay so styles that need height actually hold it.

Wavy hair gives you natural width and movement. Keep a few centimetres on top so the waves show, and avoid cutting the sides so short that the top looks heavy. Wavy hair is a gift for long and diamond faces.

Curly hair shrinks as it dries and grows outwards, so it adds width fast. Ask for a taper rather than a hard skin fade, and let your barber cut it dry or lightly damp so the length is judged correctly.

Coily hair suits short tapers, waves and twists, with a sharp line-up doing a lot of the shaping. Height on top works well for round and triangle faces.

Thinning hair looks fuller when it is shorter. Short sides and a textured top hide thin spots far better than length, which separates and shows the scalp.

More ideas: wavy hairstyles for men and curly hairstyles for men.

Knowing your face shape only helps if your barber knows what you want. Bring two or three photos of the cut on someone with a similar hair type, not just a similar face, and say what you like about each one: the height, the length at the sides or the texture.

Ask for the clipper guard numbers and the fade height before you leave, so you can repeat the cut or ask for the same thing elsewhere. Avoid vague instructions such as “short on the sides, longer on top”. They mean something different to every barber.

If you wear glasses or a beard, mention it. Heavy frames already add width at the eyes, and a beard changes the outline of the lower face, so both affect how much volume you need on top.