beta
Body Weight Interpreter

Analyzes body weight using multiple indexes, evaluates its impact on longevity, and calculates the optimal weight. Provides evidence-based nutrition and weight-loss recommendations.
Enter values
all fields are optional
 
Value
Unit
Gender
 
Weight
Height
Body fat
Waist circumference
This tool is for informational purposes only and not intended for diagnosis.

Enter values to interpret

Healthy Weight Targets

MethodologyTarget Weight
Weight at BMI 21
A BMI between 20 and 22 was associated with the lowest all-cause mortality risk among healthy never-smokers in a large meta-analysis of 30.3 million participants.

To calculate, enter value for Height.

—
Weight at BMI 25
Although a BMI of 25 falls at the top of the “healthy range”, it is associated with a 5x risk of diabetes and a 40% higher risk of coronary heart disease compared to a BMI of 21.

To calculate, enter value for Height.

—
Lean Mass Sparing Target Weight
Recommended
This calculation assumes high muscle preservation during weight loss (resistance training & adequate protein intake) and calculates the target weight based on a target body fat: 16% for men; 21% for women.

To calculate, enter values for: Weight, Height, Body fat, Gender.

—

Anthropometric Biomarkers and Ratios

Body fat: 000%

Total body fat percentage is a better predictor of cardio-metabolic risk than BMI.

BMI: 000

Body Mass Index doesn't distinguish between fat and muscle mass, so it is misleading in body building athletes. But works well for the general population.
18.5
25
30
35
40

Waist-to-Height: 000

Waist-to-Height Ratio is a better predictor of cardio-metabolic risk than BMI.
0.3
0.5
0.55
0.65

FFMI: 000

Fat-Free Mass Index is used to evaluate whether an individual has adequate muscle mass for their height. Values above 25 are suspicious for anabolic steroid use.

Why this beats ChatGPT

All research is done by humans. AI was only used to refine the writing for better readability.

  • Optimal ranges, not just “normal”

    Generic AI uses normal lab ranges (based on population averages). This tool uses functional, best-outcome targets.

  • Evidence-locked math. Not hallucinations

    Generic AI chatbots don’t know which calculated indices are best or their optimal cutoff values.

  • Quantified impact on longevity

    See the estimated impact of body weight on all-cause mortality and longevity.

  • Privacy by default

    Everything happens in your browser and no personal or medical information leaves your computer.

About the site author

My personal mission is to extend human lifespan by collectively adding 1 million years to people's lives.

That’s why I made this site 100% free—no sign-up, no email. Just instant results.

Zsolt Szabo
Zsolt Szabo
Precision Health Consultant for Longevity Clinics, Biohacker, and Software Engineer

How would you improve this tool ?

Any feedback is welcome at .