BMI Tracker
7 health metrics · free · no signup

Your Personal
Health Dashboard

Adjust the sliders — see your BMI, body fat, ideal weight, calories, protein and hydration update live.

WHO BMI standards Metric & imperial Private — no data stored For educational use
Height 175 cm
Weight 70 kg
Age 30 yrs
Sex
Activity Level
Little or no exercise
Body Composition
Body Mass Index
22.9
Normal weight
1518.5253040
Under
weight
Normal
Over
weight
Obese
Source: World Health Organization (WHO)
Healthy Weight Range
52 – 70 kg
for your height · WHO: BMI 18.5 – 24.9
✓ Within healthy range
Estimated Body Fat
18.2%
Fitness
Estimated · Deurenberg et al. (1991)
EssentialAthleticFitnessAccept.Obese
Ideal Body Weight
72kg
Devine formula
✓ You're at ideal weight
Daily Nutrition
Calorie Targets · Mifflin-St Jeor formula
Lose Weight
—
kcal / day
≈ −0.5 kg / week
Maintain
—
kcal / day
your TDEE
Gain Weight
—
kcal / day
≈ +0.5 kg / week
BMR: — kcal/day at complete rest
Mifflin & St Jeor, Journal of the American Dietetic Association, 1990
Daily Lifestyle Targets
Daily Hydration
2.3L / day
About 9 glasses (250 ml each)
Daily Protein Target
56g / day
Sedentary · 0.8 g/kg
Good sources: chicken, fish, eggs, legumes, dairy
Sources & Methodology
BMI Classification
World Health Organization (WHO)
Calorie Needs (TDEE)
Mifflin & St Jeor, 1990
Body Fat Estimate
Deurenberg et al., 1991
Ideal Body Weight
Devine formula, 1974
Hydration Guidelines
EFSA (European Food Safety Authority)
Protein Intake
WHO / ISSN guidelines
For educational purposes only. All calculations run in your browser — no data is ever sent to or stored on our servers. This tool does not constitute medical advice. BMI and body fat estimates have known limitations for muscular individuals and certain populations. Consult a qualified healthcare professional before making changes to your diet or exercise routine.

Frequently Asked Questions

All 7 metrics explained — formulas, sources, and limitations.

BMI (Body Mass Index) is your weight in kilograms divided by your height in metres squared. A BMI of 18.5–24.9 is classified as healthy weight by the World Health Organization. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is obese.
According to the WHO, a healthy BMI for adults is 18.5–24.9. This directly corresponds to your Healthy Weight Range card — the minimum and maximum body weights that fall within this band for your exact height.
BMI is a useful population-level screening tool but has well-known limitations. It can overestimate fatness in very muscular people and underestimate it in older adults who have lost muscle. The WHO recommends using BMI alongside waist circumference and body fat percentage for a fuller picture — which is exactly why this dashboard shows multiple metrics together.
The dashboard uses the Deurenberg formula (1991): BF% = (1.20 × BMI) + (0.23 × Age) − (10.8 × sex factor) − 5.4. It is a statistical estimate derived from BMI, age and sex — less precise than DEXA scanning or hydrostatic weighing, but a useful benchmark. Very muscular individuals will see an overestimate.
Per American Council on Exercise guidelines — Men: essential fat 2–5%, athletic 6–13%, fitness 14–17%, acceptable 18–24%, obese 25%+. Women: essential 10–13%, athletic 14–20%, fitness 21–24%, acceptable 25–31%, obese 32%+. These ranges are shown colour-coded on the Body Fat card above.
The Devine formula (1974) is used: 50 kg + 2.3 kg per inch over 5 feet for men, and 45.5 kg + 2.3 kg per inch for women. This formula originated in clinical medicine for drug dosing and ventilator settings. Treat it as a reference point, not a strict personal goal — healthy weight ranges vary by build and muscle mass.
TDEE (Total Daily Energy Expenditure) is the total calories your body burns per day, including activity. It's calculated by first finding your BMR (Basal Metabolic Rate) using the Mifflin-St Jeor equation, then multiplying by an activity factor ranging from 1.2 (sedentary) to 1.9 (very active). Eating at your TDEE maintains weight; 500 kcal below causes roughly 0.5 kg of fat loss per week.
A 500 kcal/day deficit below your TDEE leads to approximately 0.5 kg of fat loss per week — a rate considered safe and sustainable. Avoid going below 1,200 kcal/day (women) or 1,500 kcal/day (men) without medical supervision, as this can cause muscle loss and nutritional deficiencies.
The European Food Safety Authority (EFSA) recommends around 2.0 L/day for women and 2.5 L/day for men from all sources including food. This dashboard estimates 35 ml per kg of body weight, scaled up by activity level. In hot climates or after intense exercise, increase this further.
The WHO sets a minimum of 0.8 g per kg of body weight for sedentary adults. Active individuals need 1.4–1.6 g/kg, and athletes training hard need up to 2.0 g/kg according to ISSN research guidelines. The dashboard adjusts your protein target automatically whenever you change your activity level.
Yes. Switch between Metric (cm / kg) and Imperial (in / lbs) using the toggle at the top of the input panel. All 7 metrics — BMI, healthy weight range, body fat, ideal weight, calories, hydration and protein — recalculate instantly and display results in your chosen unit.
No. All calculations run entirely in your browser using JavaScript. Your height, weight, age and other inputs are never transmitted to or stored on our servers. Your data never leaves your device. See our Privacy Policy for full details.

GUIDES & ARTICLES

From the Blog

Featured Inspiration
The BMI Story: One Number, One Decision, One More Try
One man. 33 lbs to lose. An ankle injury, a plateau, and 23 Tuesdays he almost quit. The story of what keeping going actually looks like.
Read story →
Weight Management How to Lower Your BMI Evidence-based steps: calorie deficit, protein targets, and what the research actually says. Read → Research Does BMI Actually Matter? Where BMI is genuinely useful, where it fails, and what experts recommend instead. Read → Body Composition BMI vs Body Fat % BMI and body fat tell different stories. Learn when each measure is more useful. Read →
Browse all guides →

Understanding Your BMI Score

Body Mass Index (BMI) is a numerical value derived from your height and weight. Calculated as weight (kg) divided by height in metres squared (kg/m²), it is the most widely used population-level screening tool for healthy weight because it requires no equipment and produces an instant result. The World Health Organization divides adult BMI into four categories:

BMI Range Category Health Risk
Below 18.5 Underweight Nutritional deficiency, bone density loss
18.5 – 24.9 Healthy weight Lowest risk for most adults
25.0 – 29.9 Overweight Increased risk of cardiovascular disease
30.0 and above Obese High risk; type 2 diabetes, hypertension

A BMI in the healthy range does not guarantee good health, nor does a BMI outside it mean you are unhealthy. BMI is a screening tool, not a diagnosis. Use it alongside the body fat percentage, waist-to-height ratio, and other metrics in this dashboard to build a fuller picture.

The 7 Health Metrics This Dashboard Tracks

Most BMI calculators stop at one number. This dashboard calculates seven interconnected metrics from a single set of inputs, giving you a more complete health snapshot.

1. BMI (Body Mass Index)

The foundational metric. Calculated using the WHO formula: weight ÷ height². Fast and equipment-free, but cannot distinguish between muscle and fat mass.

2. Body Fat Percentage

Estimated using the Deurenberg formula, adjusted for age and sex. Healthy ranges differ significantly between men (6–24%) and women (14–31%). A person can have a normal BMI but high body fat — sometimes called "skinny fat" — which carries its own health risks.

3. Healthy Weight Range

The minimum and maximum weight that keeps your BMI within the WHO healthy band (18.5–24.9) for your exact height. More actionable than BMI alone: it tells you not just where you are, but the range you are aiming for.

4. Ideal Body Weight

Calculated using the Devine formula, originally developed for clinical drug dosing. It provides a single reference point, but treat it as a starting guideline — individuals vary considerably by frame size and muscle mass.

5. Daily Calorie Needs (TDEE)

Total Daily Energy Expenditure: the calories your body burns at your current weight and activity level. Calculated using the Mifflin-St Jeor equation for BMR, multiplied by your activity factor. Eating 500 kcal below your TDEE creates a deficit that results in roughly 0.5 kg of fat loss per week — the rate most widely recommended by health authorities.

6. Daily Protein Target

The WHO minimum is 0.8 g per kg of body weight for sedentary adults. Active individuals need 1.4–1.6 g/kg; athletes in hard training up to 2.0 g/kg per ISSN guidelines. The dashboard adjusts your target automatically when you change your activity level.

7. Daily Water Intake

Based on 35 ml per kg of body weight, scaled by activity level — consistent with the European Food Safety Authority's recommendation of 2.0–2.5 L/day for adults. Hot climates and intense exercise increase this further.

When BMI Gives a Misleading Picture

BMI has known blind spots that every user should understand:

For a deeper look at how BMI compares with direct body fat measurement, see our guide on BMI vs Body Fat Percentage. If you are trying to improve your score, How to Lower Your BMI walks through the evidence-based steps. And if you are questioning whether the number matters at all, Does BMI Actually Matter? gives a research-backed answer.

How to Get the Most From This Calculator

Enter your height, weight, age, sex, and activity level using the sliders at the top of the page. All seven metrics update in real time — no form submission required. A few practical tips:

All calculations run entirely in your browser. No data is ever sent to our servers — your inputs remain private.