Our Mission
The number on a scale doesn't tell the whole story — it doesn't distinguish muscle from fat, and it fluctuates daily due to water and food, not real progress. BodyWeightCalculator.org gives you body composition estimates (via the Navy Method or a quick BMI-based estimate) plus a moving-average trend tracker that reveals what's actually changing.
Our Methodology
Our Quick Estimate uses the Deurenberg formula (BMI, age, and gender-based). Our Navy Method uses circumference measurements (neck, waist, and hip for women) for a generally more accurate estimate. Our Weight Trend Tracker applies a simple moving average to smooth out day-to-day fluctuations.
Important: we are an informational resource, not a medical provider. Read our full Disclaimer before making health decisions based on any calculator result.
Editorial Standards
We're upfront about accuracy limits — Navy Method typically has a few percentage points of error versus clinical DEXA scans, and we say so clearly rather than overselling precision.
What We're Building Next
We're exploring additional body composition formulas (like the Jackson-Pollock skinfold method) and export options for the trend tracker, continuing the same standard: transparent math, no dark patterns, free forever.
Free, Always
No paywalls, no account required, no hidden premium tier.
Beyond the Scale
Composition and trend, not just a single weight number.
Privacy-First
Your inputs never leave your browser or touch our servers.