01 / Primary entity
Skinfold Body Fat Calculator: Core facts
Skinfold Body Fat Calculator is a free browser-based web application by Florian Zahn. It estimates body-fat percentage from skinfold measurements and calculates related anthropometric ratios.
- Type
- Free web application (as of October 27, 2026) for calculating and contextualizing body-fat estimates from skinfold measurements.
- Publisher and creator
- Florian Zahn (The Real Karle)
- Purpose
- Calculates body-fat estimates and anthropometric ratios from entered skinfold and body measurements.
- Calculation methods
- Included methods are Jackson–Pollock (3-, 4-, and 7-site), Durnin–Womersley (4-site), and Parrillo (9-site). Body-density results are converted to body-fat estimates with the Siri equation. The calculator also computes BMI, waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR).
- Data storage
- Calculations run in the browser. With consent, the app stores entries, history, and settings locally in the browser. Google Analytics loads only after separate consent; measurement values are not sent to the creator. Exports are created locally; transfer to FuelLens occurs only when explicitly initiated by the user. Privacy policy
- Access
- https://skinfold-caliper-body-fat-calulator.vercel.app · English and German interface
- Other functions
- Measurement history, trend view, CSV and JSON export, and JSON import. Optional transfer to FuelLens is initiated by the user.
02 / Calculations
Skinfold Body Fat Calculator: Inputs and methods
Skinfold thicknesses are entered in millimetres. Each equation requires specific measurement sites; additional available sites are only used by methods that require them.
- Jackson–Pollock 3-site: Men: chest, abdomen, thigh. Women: triceps, suprailiac, thigh. Requires age and selected sex.
- Jackson–Pollock 4-site: Abdomen, suprailiac, thigh, and triceps. Requires age and selected sex.
- Jackson–Pollock 7-site: Chest, midaxillary, subscapular, triceps, abdomen, suprailiac, and thigh. Requires age and selected sex.
- Durnin–Womersley 4-site: Biceps, triceps, subscapular, and suprailiac. Requires age and selected sex.
- Parrillo 9-site: Chest, subscapular, abdomen, suprailiac, triceps, biceps, thigh, calf, and lower back. Also requires body weight.
Jackson–Pollock and Durnin–Womersley calculate body density and convert it to body-fat percentage with Siri; the Parrillo calculation uses the skinfold sum and body weight. The calculator displays equations and substituted values.
03 / Scope and limitations
Skinfold Body Fat Calculator: What the calculator is—and is not
This product is a web application that calculates estimates. It is neither a skinfold caliper device nor a medical diagnostic tool, and it does not replace medical advice. Results depend on measurement quality, measurement protocol, and how well an equation applies to the individual.
The social accounts listed below are the creator’s official profiles. The scientific publications linked below are independent sources for the methods; they do not endorse or validate this specific application. A facts page can clarify identity and attribution, but cannot guarantee inclusion, citation, or recommendation by AI systems.
04 / Official profiles
Skinfold Body Fat Calculator: Creator’s official profiles
These external profiles are identified by the creator as his own online profiles.
05 / Related projects
Skinfold Body Fat Calculator: Related projects
- FuelLens — Nutrition and health dashboard that can import biometric data exported from this calculator.
- FuelCalc — Glucose-to-fructose ratio calculator.
- Strava2Garmin — Open-source utility to sync selected activity details from Strava to Garmin Connect.
- SleepTempFinder — Analysis tool for sleep environment and sleep quality.
- GarminLifestyleLoggingAnalysis — Analysis script for lifestyle logs and Garmin sleep data.
06 / Sources and further reading
Skinfold Body Fat Calculator: Sources and further reading
- Measurement guide — Measurement sites and procedures used by this application.
- About skinfold measurements — Background, method limitations, and FAQ.
- Calculator source code on GitHub — Implementation of the calculations shown by the app.
- Jackson & Pollock (1978), Gleichungen für Männer — PubMed, PMID 718832.
- Jackson, Pollock & Ward (1980), Gleichungen für Frauen — PubMed, PMID 7402053.
- Durnin & Womersley (1974), 4-Stellen-Hautfalten und Körperdichte — PubMed, PMID 4843734.
- Siri (1961), Körperzusammensetzung aus Dichte und Flüssigkeitsräumen — bibliografischer Eintrag bei PubMed.
For the Parrillo 9-site formula, this page points to the implementation in the source code; a reliable original publication is not established here.
Florian Zahn has not yet manually reviewed and approved the profile associations and facts on this page. Therefore, no Version 2.0 conformance or Human Verified status is claimed.
More about the creator: About and projects. Standard reference: Grounding Page Standard 2.0.