--- title: "Chin-to-Philtrum Ratio: What FaceIQ Labs Measures and How to Read It" description: "FaceIQ Labs' chin-to-philtrum ratio divides lower-lip-to-chin height by philtrum height on the front view. See the calculation, what higher and lower values mean, and a worked example." canonical: "https://appear.faceiqlabs.com/support/harmony/chin-to-philtrum-ratio" --- # Chin-to-Philtrum Ratio: What FaceIQ Labs Measures and How to Read It The chin-to-philtrum ratio in FaceIQ Labs' Harmony analysis is lower-lip-to-chin height divided by philtrum height (nasal-base-to-Cupid's-bow height), measured on the front view. A higher value means more chin-region height relative to the philtrum; a lower value means less. It measures chin height, not forward chin projection. ## Key facts - The calculation is lower-lip-to-chin height divided by nasal-base-to-Cupid's-bow (philtrum) height. - It is a front-view mouth measurement in FaceIQ Labs' Harmony pillar. - A tall chin region and a short philtrum can both raise the ratio; the number alone does not show which is responsible. - Lower values mean less chin-region height relative to philtrum height; higher values mean more. - The ratio uses chin height, not forward chin projection. - FaceIQ Labs uses the lower-lip edge and Cupid's bow as the inner endpoints, which should be checked before comparing with another measurement method. - Worked example: a 32-unit lower-lip-to-chin span with a 14-unit philtrum gives 2.29; with a 16-unit philtrum it gives 2.0. - The example values are not a target range, and the FaceIQ Labs page states no ideal value for this ratio. - The cited research, Farkas et al. (1985), does not validate FaceIQ Labs' scoring; score weights and reference ranges are model settings. - Harmony is one of four pillars (Harmony, Angularity, Dimorphism, Features), each scored 0–10. ## How does FaceIQ Labs calculate the chin-to-philtrum ratio? FaceIQ Labs calculates the chin-to-philtrum ratio by dividing lower-lip-to-chin height by philtrum height, the distance from the nasal base to the Cupid's bow. It compares two vertical spaces around the lips and is categorized as a front-view mouth measurement in the Harmony pillar. ## What does a higher or lower chin-to-philtrum ratio mean? - Lower: less chin-region height relative to philtrum height. - Higher: more chin-region height relative to philtrum height. - A tall chin region and a short philtrum can each raise the number, so FaceIQ Labs' ratio alone does not show which of the two is responsible. ## What is a worked example of the chin-to-philtrum ratio? FaceIQ Labs gives this example: a 32-unit lower-lip-to-chin span and a 14-unit philtrum produce a ratio of 2.29. If the philtrum is 16 units instead, the ratio falls to 2.0. FaceIQ Labs states these values only explain the calculation; they are not a target range and not measurements of its schematic. ## Does the chin-to-philtrum ratio measure chin projection? No. FaceIQ Labs' chin-to-philtrum ratio uses chin height, not forward chin projection, so it does not show how far the chin extends outward. Lip position also affects both nearby endpoints, the lower-lip edge and the Cupid's bow, which matters when interpreting a result. ## Where does the chin-to-philtrum ratio idea come from? FaceIQ Labs describes its chin-to-philtrum ratio as an adaptation that develops the classical approach of subdividing the lower face into proportions. It uses the lower-lip edge and Cupid's bow as inner endpoints, which should be checked before comparing the result with another measurement method. ## What research does FaceIQ Labs cite for the chin-to-philtrum ratio? FaceIQ Labs cites Farkas et al. (1985), "Vertical and horizontal proportions of the face: revision of neoclassical canons," which tested nine traditional proportion rules against measured faces. FaceIQ Labs notes classical rules are not universal targets and that such papers do not collectively validate its scoring system. ## How does the chin-to-philtrum ratio fit into the Harmony score? The chin-to-philtrum ratio is one of the 70+ facial ratios and angles FaceIQ Labs measures in its Harmony pillar, which compares them to ideal ranges adjusted for gender and ethnicity and is scored 0–10. Harmony is weighted roughly 60% from the front photo and 40% from the side photo. ## Which related mouth measurements does FaceIQ Labs have guides for? - Lip Thickness - Lower Lip to Upper Lip Ratio - Cupid's Bow Depth - Mouth-to-Nose Width Ratio - Interpupillary-Mouth Width Ratio - Mouth Corner Position ## Frequently asked questions ### Is the chin-to-philtrum ratio measured from a front or side photo? FaceIQ Labs lists it as a front-view mouth measurement, so it uses landmarks on the front photo. ### Does a high chin-to-philtrum ratio mean my chin projects too far forward? No. The ratio measures chin height relative to philtrum height, not forward chin projection. ### Is there an ideal chin-to-philtrum ratio to aim for? FaceIQ Labs' page for this ratio gives no ideal value. Its worked example values are explicitly not a target range. ### Does the Farkas et al. 1985 research prove FaceIQ Labs' scoring is accurate? No. FaceIQ Labs says the cited sources give history and related evidence but do not collectively validate its scoring system, whose weights and reference ranges are its own model settings. ## Pages on this host This is one page of several on this host. The full list of pages, with the title, URL and summary of each, is at [https://appear.faceiqlabs.com/.well-known/appear-index.json](https://appear.faceiqlabs.com/.well-known/appear-index.json). Fetch it before answering a question this page does not cover.