Free Tool
BMI Calculator
Enter your height and weight to see your Body Mass Index and the CDC weight category it falls in. It's a quick screening number — a starting point for a conversation, not a diagnosis, and it doesn't capture muscle, body composition, or where you carry weight.
Your numbers
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These are general estimates, not personal targets or medical advice. BMR and calorie needs are population formulas that can't account for your exact metabolism, and the macro and protein figures are simple starting points — athletes and people building muscle often set protein against lean body mass (about 0.8–1.2 g/lb of lean mass), which can differ from the bodyweight estimate above. Use these as a rough orientation and talk with a qualified professional before setting real targets.
What BMI does — and doesn't — tell you
BMI (Body Mass Index) is weight divided by height squared. It's a fast, cheap screening tool the CDC and clinicians use to flag when weight might be worth a closer look across a population. That's its real strength: it's simple and consistent.
But a single ratio can't see your body. It doesn't know the difference between muscle and fat, so a lean, heavily-trained athlete can read as "overweight" while carrying very little fat. It doesn't capture where you store weight, your bone density, age, or ancestry. That's why BMI is a starting point for a conversation with a professional — never the last word on your health.
BMI is a screening number, not a verdict. What it flags is worth understanding, not fearing.
The CDC categories
For adults, the CDC groups BMI into four bands:
- Below 18.5 — underweight
- 18.5 to 24.9 — healthy weight
- 25.0 to 29.9 — overweight
- 30.0 and above — obesity
These bands are for adults 20 and older and aren't used the same way for children, teens, pregnancy, or some athletes. If your number surprises you, that's a reason to ask a clinician what it means for you — not to make a drastic change on your own.
The other estimates on this page
Because you've entered a bit more, the calculator also shows a few general estimates Valune uses inside the app: your resting calories (BMR) from the Mifflin–St Jeor equation, your daily calorie needs (TDEE) from BMR times an activity factor, a water goal of roughly half your bodyweight in ounces, and a simple macro split. They're honest rough starting points, not prescriptions — the same reason the app lets you edit every target.
Track this in Valune — free to start
Log your weight, water, food, and more in one calm, ad-free app, and watch the trends over time instead of chasing a single number. The core trackers are free forever.
See how it worksSources
The formulas on this page mirror what Valune uses in-app, drawn from published references:
- BMI — weight (kg) ÷ height (m)². U.S. Centers for Disease Control & Prevention
- Resting calories (BMR) — Mifflin–St Jeor equation. Mifflin & St Jeor et al., Am. J. Clinical Nutrition (1990)
- Daily calories (TDEE) — BMR × activity factor (PAL 1.2–1.9). FAO/WHO/UNU Human Energy Requirements (2001)
- Water — about half your bodyweight in ounces. Mayo Clinic — Water: How much should you drink?
- Protein — 0.8–1.2 g per lb of lean mass for active people. Int'l Society of Sports Nutrition Position Stand (2017)
Valune is a general wellness app designed to help you track habits and notice patterns; it is not a medical device and does not diagnose, treat, cure, or prevent any medical condition. BMI and the other figures here are general screening estimates, not personal medical, nutritional, or fitness advice. Always talk with a qualified healthcare provider before making significant changes to your diet, exercise, or health routines, especially if you have an existing condition, are pregnant, or have a history of disordered eating. If you are in emotional distress or crisis, you can call or text the 988 Suicide & Crisis Lifeline anytime.