Calculate your Body Mass Index. Get your category, healthy weight range, waist risk, body fat estimate, and a personalised goal timeline.
Imperial & MetricWaist RiskGoal TimelineAction Plan
📐 Enter Your Measurements
Metric (kg / cm)
Imperial (lbs / ft·in)
kg
cm
lbs
ft
in
For Detailed Analysis + Waist Risk
yrs
cm
in
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Where You Sit on the Weight Spectrum
YOU
UnderweightNormalOverweightObese
BMI Scale (15 – 45)
UnderweightNormalOverweightObese
Healthy Range
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BMI 18.5 – 24.9
To Healthy Weight
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lose / gain
Ideal Body Weight
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Devine formula
Body Fat Est.
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Deurenberg formula
📏 Waist Circumference Risk
Waist size predicts visceral fat and metabolic risk more accurately than BMI alone. Enter your waist measurement above to unlock this section.
← Enter waist circumference in the input card above
Low RiskElevatedHigh Risk
Waist Size
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your measurement
Waist-to-Height
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target: < 0.50
Visceral Risk
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WHO threshold
⏱️ Timeline to Healthy Weight
Based on a sustained caloric deficit — no crash dieting.
✅ You're already in the healthy BMI range (18.5–24.9). Focus on maintaining through diet and activity.
🐢 Sustainable Pace
— weeks
500 cal/day deficit · ~0.5 kg/week
⚡ Faster Pace
— weeks
1,000 cal/day deficit · ~1 kg/week · requires resistance training
🌱 Lean Bulk
— weeks
+300 cal/day surplus · ~0.25 kg/week
📈 Standard Bulk
— weeks
+500 cal/day surplus · ~0.4 kg/week
🗺️
Your Personalised Action Plan
3 steps based on your current BMI
1
Calculate and hit your loading...
Enter your measurements above for a personalised plan.
WHO BMI Categories
Category
BMI Range
Health Risk
⚠️ What BMI Doesn't Tell You
BMI is a population screening tool. These 6 factors mean two people with the same BMI can have very different health profiles.
💪
Muscle Mass
Muscle weighs more than fat. A 200 lb athlete at 5'10" is BMI 28.7 (overweight) but may have only 10% body fat.
🫀
Fat Distribution
Visceral fat (around organs) is far more dangerous than subcutaneous fat. Two people with BMI 28 can have completely different cardiac risk.
🧬
Ethnicity
Asian populations face higher metabolic risk at lower BMI thresholds. WHO recommends using BMI 23 as overweight and 27.5 as obese for Asian adults.
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Age
Older adults naturally lose muscle and gain fat. A BMI of 26 may reflect healthy body composition at 60 but excess fat at 25.
🦴
Bone Density
Heavy bone structure raises BMI without any extra fat. Conversely, osteoporosis can mask low BMI severity in older women.
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Better Alternatives
Waist-to-height ratio (<0.5), waist circumference, body fat % via DEXA, and metabolic blood panels give a more complete picture.
⚕️ Important: BMI is a population-level screening tool, not a diagnostic measure. It does not account for muscle mass, bone density, age, ethnicity, or fat distribution. Always consult a healthcare provider for a comprehensive health assessment.
Frequently Asked Questions
What is a healthy BMI for adults?+
According to the WHO, a healthy BMI for most adults is 18.5–24.9. Below 18.5 is underweight; 25–29.9 is overweight; 30 and above is obese. These are population-level guidelines — individual health depends on body composition, fitness level, blood markers, and metabolic health.
Is BMI accurate for athletes and muscular people?+
No — BMI significantly overestimates body fat in muscular individuals. A 200-pound athlete at 5'10" has BMI 28.7 but may have only 10–12% body fat. For athletes, body composition testing via DEXA scan, hydrostatic weighing, or bioelectrical impedance gives a far more accurate picture.
How can I lower my BMI?+
BMI decreases when you lose body fat, requiring a sustained caloric deficit. A deficit of 500 cal/day yields ~0.5 kg/week fat loss. Combining a reduced-calorie diet with resistance training is optimal — it preserves lean muscle while reducing fat mass. Use the Calorie Calculator to find your TDEE and set a target.
What is the BMI formula?+
Metric: BMI = weight (kg) ÷ height² (m²). Example: 75 kg at 175 cm = 75 ÷ (1.75²) = 24.5. Imperial: BMI = (weight in lbs × 703) ÷ height² (inches²). Example: 165 lbs at 5'9" (69 in) = (165 × 703) ÷ 69² = 24.4.
What is waist-to-height ratio and why does it matter?+
Waist-to-height ratio (WHtR) = waist circumference ÷ height. A WHtR below 0.50 is considered healthy for most adults and is a stronger predictor of cardiovascular and metabolic disease than BMI. The rule of thumb: "keep your waist to less than half your height." It accounts for body fat distribution in a way BMI cannot.
What are better metrics than BMI?+
Several metrics give more detail: (1) Waist circumference — risk increases above 88 cm/35 in (women) or 102 cm/40 in (men). (2) Waist-to-height ratio — keep below 0.5. (3) Body fat % via DEXA, hydrostatic weighing, or calipers. (4) Waist-to-hip ratio — WHO risk: above 0.90 (men) or 0.85 (women). Using 2–3 metrics together gives a far better picture.