Know your numbers
before you chase them.
BMI (Body Mass Index), BMR (Basal Metabolic Rate), daily calories (TDEE), and water intake — worked out precisely, explained plainly, and logged the old-fashioned way. No account, no upsell, no wondering what happened to your data.
01
Full Health Report
Every number below, worked out together from one set of inputs — and a PDF you can keep or share.
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02
Body Mass Index (BMI) Calculator
Weight relative to height, plotted on the standard adult scale, with a dial to show where you land.
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03
Basal Metabolic Rate (BMR) Calculator
The energy your body burns at complete rest — the number every diet plan should start from.
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04
Daily Calorie & TDEE Calculator
Your BMR adjusted for how you actually move through the week, from desk-bound to twice-a-day training.
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05
Water Intake Calculator
A daily hydration target adjusted for your weight, the climate, and how hard you're training.
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From the journal
See all posts →
Notes worth reading before you weigh in
Weight gain
7 min
Gaining weight healthily as an adult — the real numbers
Underweight gets a fraction of the attention weight loss does. Here's a sane, muscle-first approach to putting on weight.
Read →
BMI
6 min
Underweight BMI: what it actually means, and what to do next
A low BMI reading raises different questions than a high one. Here's how to read it properly.
Read →
Data
6 min
Why India's weight numbers are moving in two directions at once
Rising obesity and persistent underweight rates, side by side — what the 2026 data actually shows.
Read →
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Why another calculator site?
Most BMI tools bury the number in banner ads and pop-ups. Wellnum does one thing: takes your inputs, shows the working, and gets out of your way. Read more about the formulas and their limits in the journal.