BMI Calculator
Calculate your Body Mass Index and see your healthy weight range, in metric or imperial units.
Last updated August 1, 2026
How to use the BMI calculator
- 1
Select metric (centimeters and kilograms) or imperial (feet, inches, and pounds) units.
- 2
Enter your current height and weight.
- 3
Your BMI score, weight category, and healthy weight range update instantly.
BMI formula: how to calculate body mass index
Body Mass Index was developed in the 1830s by Belgian mathematician Adolphe Quetelet as a simple way to describe relative weight across large populations. It has since become the standard screening metric used by the World Health Organization, the CDC, and physicians worldwide. This calculator uses the same 18.5 / 25 / 30 category thresholds published by both agencies.
Metric formula: BMI = weight in kilograms ÷ (height in meters)²
Imperial formula: BMI = 703 × weight in pounds ÷ (height in inches)²
Example (metric): A person who weighs 70 kg and is 1.70 m tall has a BMI of 70 ÷ (1.70 × 1.70) = 70 ÷ 2.89 = 24.2, which falls in the healthy weight category.
Example (imperial): A person who weighs 154 lb and is 5'7" (67 inches) tall has a BMI of 703 × 154 ÷ (67 × 67) = 108,262 ÷ 4,489 = 24.1. That's basically the same result as the metric example above, since the two formulas are the same math in different units.
Once you know your BMI and healthy weight range, the next question is usually how many calories to eat to get there. Our TDEE & BMR calculator turns your height, weight, and activity level into a daily calorie target for weight loss, maintenance, or muscle gain.
| BMI range | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obesity |
BMI chart: healthy weight by height
This BMI chart shows the weight (in pounds) that marks each BMI category boundary for common adult heights, so you can see where you fall without entering numbers into the calculator above. Find your height, then compare your weight to the healthy, overweight, and obesity thresholds next to it.
| Height | Healthy weight (18.5–24.9) | Overweight starts at | Obese starts at |
|---|---|---|---|
| 4'10" (58 in) | 89 – 119 lb | 120 lb | 144 lb |
| 5'0" (60 in) | 95 – 127 lb | 128 lb | 154 lb |
| 5'2" (62 in) | 101 – 136 lb | 137 lb | 164 lb |
| 5'4" (64 in) | 108 – 145 lb | 146 lb | 175 lb |
| 5'6" (66 in) | 115 – 154 lb | 155 lb | 186 lb |
| 5'8" (68 in) | 122 – 163 lb | 164 lb | 197 lb |
| 5'10" (70 in) | 129 – 173 lb | 174 lb | 209 lb |
| 6'0" (72 in) | 136 – 183 lb | 184 lb | 221 lb |
| 6'2" (74 in) | 144 – 194 lb | 195 lb | 234 lb |
| 6'4" (76 in) | 152 – 204 lb | 205 lb | 246 lb |
These figures come directly from the same formula the calculator above uses — weight (lb) = BMI × height (in)² ÷ 703 — solved for the 18.5, 25, and 30 BMI thresholds at each height. If your height falls between two rows, or you use metric units, enter your exact numbers into the calculator above for a precise result instead of an estimate from the chart.
Limitations of BMI and healthy weight ranges
While BMI is fast and free to calculate, it has well-documented limitations. Because it only considers height and total body weight, it cannot distinguish between muscle mass, bone density, and fat mass. A bodybuilder and a sedentary person of the same height and weight will have identical BMI scores despite very different body compositions and health risk profiles.
BMI thresholds also don't adjust for age, sex, or ethnicity, even though research shows body fat distribution and associated health risks can vary across these groups at the same BMI value. For a more complete picture, healthcare providers often combine BMI with waist circumference, waist-to-hip ratio, or direct body composition measurements like DEXA scans or bioelectrical impedance analysis.
Even with those caveats, BMI still earns its place. It's quick, free, and needs no special equipment, which makes it a solid first-pass screening tool for population studies and a reasonable personal benchmark to track over time.
For a more direct estimate of body composition, our Body Fat Calculator uses the U.S. Navy circumference method to estimate your actual body fat percentage, fat mass, and lean mass.
Want an actual target weight instead of a ratio? Our Ideal Body Weight Calculator estimates a weight range from height and sex using four standard clinical formulas.