Facial depth to height ratio

The facial depth to height ratio, often shortened to FDHR, is a forum measurement that compares how far the face projects from front to back with how tall the face is. It borrows its shape from the better-known width-to-height ratio, but it needs a side view, and that is where most online numbers go wrong. This guide explains the ratio, how people try to measure it, why a front photo cannot give it, and what a careful side photo can and cannot tell you.

What the facial depth to height ratio compares

Depth is the front-to-back dimension of the face. Height is the vertical distance from an upper landmark to the chin. Dividing one by the other gives a single number that is meant to describe how flat or projecting the face looks from the side. A face with a high value would be deeper for its height, and a low value would be flatter.

Posts that use it do not agree on landmarks. Some measure depth from the ear canal area to a point on the front of the face, others to the nose tip or the brow. Some take height from the brow or the nasion to the chin, others from the hairline. A different choice of points can change the result a lot, so a number from one thread cannot be compared with a number from another.

How it differs from the width-to-height ratio

The fwhr ratio divides the width of the face across the cheekbones by the height of the upper face. Both numbers are on the same flat plane, so a front photo can measure them. FDHR swaps width for depth, which lives on a different axis. You can see the width of the face in a front photo, and you cannot see how far the nose or chin sticks out of it.

The face proportions tool puts several front-view ratios side by side, such as eye spacing and face length to width. None of those is depth, and none of them stands in for it.

Why a front photo cannot measure facial depth

A camera turns a three-dimensional face into a flat picture. In a front photo, depth is folded into the image, and what remains are indirect hints such as shading. Face-landmark software does output a third coordinate for each point, but that value is a relative estimate learned by a model, not a measured distance. It has no reliable scale, and it changes with pose, expression and lens. Treating it as millimetres of depth would produce a precise-looking number with little meaning behind it.

That is why this site does not offer an FDHR calculator for front photos. Any tool that gives you one from a selfie is guessing. A real value comes from a side view, a caliper on the face, or a 3D scan, each with its own error.

Measuring from a side photo

If you still want to try, a side photo is the least bad option. Stand with your head level, as when you look at the horizon, and have someone hold the camera at face height, a few metres away, using the zoom instead of getting close. A close lens enlarges the nose and shortens the ear-to-face distance. Keep the whole head in view, with a relaxed face and the mouth closed. Then place your chosen landmarks, write down which ones you used, and use the same ones next time.

Even then, the facial depth to height ratio is a rough number from one pose. A small head tilt shifts the depth, and a different distance shifts it again. The photo guide lists the rules for a fair image, and the perfect side profile tool shows forehead, nose, lip and chin position from a side photo, which is a safer way to look at projection than one ratio.

What the facial depth to height ratio is not

There is no accepted ideal facial depth to height ratio. Forum threads sometimes quote a target, but those figures come from posters, not from research, and no study supports a particular number as better looking or healthier. Because the landmarks vary, a quoted target cannot even be reproduced. Do not use one to judge your face, and do not use it to decide that something needs surgery or other treatment.

Depth is also only one part of how projection reads. Related terms such as recessed maxilla and gonial angle describe where the midface and the jaw sit, and the face structure guide explains how bone and soft tissue combine. Hair, beard, weight and light change how deep a face looks without changing the bone.

Keeping a ratio in proportion

A number can look scientific without being useful. If measuring FDHR starts to take up a lot of time, or you feel worse each time you measure, stop and talk to someone you trust or a health professional. Questions about jaw position, breathing or bite belong with a dentist or doctor, not with a forum figure. A PSL rating describes one photo and does not claim to measure depth.

Facial depth to height ratio FAQ

What is the facial depth to height ratio?

It is a forum measurement that divides a front-to-back facial distance by a face height. Definitions vary between posts.

Can I measure it from a selfie?

No. A front photo does not contain reliable depth. Use a side photo and note which points you used.

Is there an ideal value?

No. Numbers quoted online come from forum posts and have no research behind them.

Is the facial depth to height ratio the same as FWHR?

No. FWHR uses width, which a front photo can show. FDHR uses depth, which needs a side view.

Does this site calculate it?

No. The side profile tool describes the shape of a side photo, and it does not output this ratio.

Should a low or high ratio worry me?

No. It is an informal figure and not a medical measurement. See a professional for health questions.