The BMI Metrics blog

The numbers,
explained.

Short, practical guides behind each calculator — what the formula measures, where it breaks down, and how to actually use the result.

GUIDE · 01

Understanding BMI: what it measures and what it misses

BMI is one number calculated from two others — but it was never meant to be read in isolation. Here's what it's actually good for.

GUIDE · 02

Calorie deficits, explained without the hype

How BMR and TDEE relate to weight change, why "eat less, move more" is true but incomplete, and how to set a deficit that's sustainable.

GUIDE · 03

How much water do you actually need?

The "8 glasses a day" rule isn't wrong, exactly — it's just not personalized. Here's a better way to estimate your number.