Oblong Face Shape: Why Two Width Formulas Give Different Ratios

An oblong face looks elongated with relatively straight sides; if your outline tapers from the cheeks toward the chin, compare it with oval before choosing a label.

When two guides give you different ratios, check what each one calls width. One may use your cheekbone width. Another may average your forehead, cheekbone and jaw widths. Those are different inputs to the calculation, even when every measurement stays exactly the same.

Oval or oblong: keep the outline beside the numbers

A long face and a tapered jaw can appear together. Keep both observations in your notes instead of discarding one to make a label fit. The calculations below isolate one narrower question: how much does the width definition change the ratio?

Our reproducible comparison: same inputs, different denominators

We ran this calculation on September 23, 2026, using deliberately constructed example inputs. These are synthetic test fixtures, not measurements of people. We calculated both formulas locally, repeated the calculation with unchanged inputs, and saved the raw outputs.

Use L for length, F for forehead width, C for cheekbone width and J for jaw width. All four inputs use the same length unit. For this comparison, widths are straight spans; a jaw measurement taken along the jaw contour would be a different input definition.

Average-width ratio = L / ((F + C + J) / 3)

Cheekbone-width ratio = L / C

A: the average-width result is higher

In example A, the forehead width is 13, cheekbone width is 14 and jaw width is 12. Their average is 13. Dividing the unchanged length of 20 by that average gives 1.5385; dividing it by the cheekbone width gives 1.4286. The unrounded outputs differ by 0.1098901099. Only the denominator changed between those two calculations.

The relative increase is 7.69%, calculated as ((20 / 13) / (20 / 14) - 1) × 100. Both inputs to that percentage come from row A. It describes the difference between these two calculated ratios, not the probability that someone has an oblong face.

B: equal widths remove the difference

Example B keeps length at 20 and sets all three widths to 14. Their average is also 14. Both formulas return 1.4285714286, so the difference is zero. This control checks that our comparison agrees when its two denominators agree.

C: the direction can reverse

Example C keeps length at 20 and cheekbone width at 14, but uses 15 for both forehead and jaw width. The average is 44 / 3. The average-width result is 1.3636363636, below the cheekbone-width result of 1.4285714286. The difference is -0.0649350649, or -4.55% relative to the cheekbone-width result, calculated as ((20 / (44 / 3)) / (20 / 14) - 1) × 100.

Across A, B and C, the cheekbone-width calculation stays fixed because its inputs stay at 20 and 14. The average-width calculation changes because it also includes the forehead and jaw values. Repeating each row with its original inputs produced identical outputs. This is a repeatable formula comparison; we did not obtain or compare labels from the competing detectors.

Use the result when two face-shape answers disagree

Write the denominator next to any ratio you save: cheekbones only, or the average of named widths. Compare numbers only after their definitions match. A ratio without that definition leaves out information you need to reproduce it.

For a mixed outline, keep separate notes for length, side curvature and jaw taper. Then use the tool's stated input method consistently. Our example A produces two different ratios from unchanged measurements; it gives you a concrete reason to check the calculation before treating a changed number as a changed face.

Download the calculation record to inspect every input and rerun the comparison. Keep your own measurement record separate from these synthetic examples.

Download the inputs and results (CSV) · Download full calculation log (JSON)