About me & projects

01 / About me

Tools built to answer practical questions

I’m Florian Zahn, also known online as The Real Karle. I build tools that help people make better sense of personal data.

I am a competitive 800-metre runner at TV Konstanz, and I also enjoy road cycling. Training has made me curious about the connection between measurement, recovery, and performance.

02 / Why this calculator?

Transparent body-fat estimates

I built the Skinfold Body Fat Calculator to make body-fat estimates from caliper measurements easier to understand and compare. It shows the inputs and formulas behind each result and helps you track body-composition measurements over time.

The calculator is designed for personal use. Your measurements stay in this browser unless you choose to export or transfer them.

If you find a bug or would like to see a feature, feel free to message me on Instagram.

03 / My other apps & websites

Most relevant projects

FuelLens

A nutrition and health dashboard for analysing data from apps such as Cronometer and MyFitnessPal. It can also import biometric measurements from this calculator.

FuelCalc

A glucose-to-fructose ratio calculator to help plan carbohydrate intake for endurance sports.

Strava2Garmin

A Python tool for Windows that syncs activity names, descriptions and optional event categories from Strava to Garmin Connect.

SleepTempFinder

An R-based analysis tool for exploring relationships between sleeping-room temperature, humidity, and sleep-quality metrics.

GarminLifestyleLoggingAnalysis

An R script that combines daily lifestyle logs with Garmin sleep data and analyses changes in sleep quality, including p-values.

Other projects