BMI Calculator – Calculate Your BMI by Height & Weight
BMI Calculator
Enter your height and weight to get your BMI, weight category and healthy weight range for your height.
For adults age 20 and older. Your numbers stay in your browser and are never sent anywhere.
BMI is a screening measure, not a diagnosis. Talk to a healthcare professional about your result.
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By Nintoz Team · Last updated: November 2026. This BMI calculator uses the adult categories published by the CDC.
What Is BMI?
Body Mass Index (BMI) is a number calculated from your weight and height. It is a quick, low-cost screening tool that places an adult in one of four groups: underweight, healthy weight, overweight or obesity. It does not measure body fat directly and does not diagnose a health condition.
How to Use the BMI Calculator
- Choose US Units (feet, inches, pounds) or Metric Units (cm, kg).
- Enter your height. In US units you can leave inches blank if you are an exact number of feet.
- Enter your weight, ideally measured in the morning without heavy clothing.
- Select Calculate BMI to see your BMI, category, healthy weight range and BMI Prime.
- Use Copy, Download, Print or Share to save your result.
BMI Formula and Examples
Metric: BMI = weight (kg) ÷ height² (m). US: BMI = [weight (lb) ÷ height² (in)] × 703.
US example: 5 ft 10 in (70 in) and 175 lb → (175 ÷ 4,900) × 703 = 25.1, which is in the overweight category, just above the healthy limit.
Metric example: 178 cm (1.78 m) and 79 kg → 79 ÷ 3.17 = 24.9, which is in the healthy weight category.
Need to convert or compare numbers? Try the Ratio Calculator or the Fraction Calculator.
Adult BMI Categories
The CDC applies the same cut-offs to all adults age 20 and older, regardless of sex.
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 to 24.9 | Healthy weight |
| 25.0 to 29.9 | Overweight |
| 30.0 to 34.9 | Obesity, Class 1 |
| 35.0 to 39.9 | Obesity, Class 2 |
| 40.0 or higher | Obesity, Class 3 |
The World Health Organization uses the same main cut-offs and adds finer grades of thinness below 18.5.
Healthy Weight Range by Height
This BMI chart shows the approximate weight range that keeps an adult at BMI 18.5 to 24.9 for each height, in pounds and kilograms. Values are rounded.
| Height | Healthy weight (lb) | Healthy weight (kg) |
|---|---|---|
| 4′10″ (147 cm) | 89–119 lb | 40–54 kg |
| 4′11″ (150 cm) | 92–123 lb | 42–56 kg |
| 5′0″ (152 cm) | 95–128 lb | 43–58 kg |
| 5′1″ (155 cm) | 98–132 lb | 44–60 kg |
| 5′2″ (157 cm) | 101–136 lb | 46–62 kg |
| 5′3″ (160 cm) | 104–141 lb | 47–64 kg |
| 5′4″ (163 cm) | 108–145 lb | 49–66 kg |
| 5′5″ (165 cm) | 111–150 lb | 50–68 kg |
| 5′6″ (168 cm) | 115–154 lb | 52–70 kg |
| 5′7″ (170 cm) | 118–159 lb | 54–72 kg |
| 5′8″ (173 cm) | 122–164 lb | 55–74 kg |
| 5′9″ (175 cm) | 125–169 lb | 57–76 kg |
| 5′10″ (178 cm) | 129–174 lb | 58–79 kg |
| 5′11″ (180 cm) | 133–179 lb | 60–81 kg |
| 6′0″ (183 cm) | 136–184 lb | 62–83 kg |
| 6′1″ (185 cm) | 140–189 lb | 64–86 kg |
| 6′2″ (188 cm) | 144–194 lb | 65–88 kg |
To measure a percentage change in weight over time, use the Percentage Calculator.
What Is BMI Prime?
BMI Prime is your BMI divided by 25, the upper limit of the healthy range. A value below 0.74 is underweight, 0.74 to 0.99 is healthy, and 1.0 or above is overweight or higher. It is shown in the result as a simple way to see how far you are from the upper healthy limit.
BMI for Men, Women and Older Adults
The CDC uses the same adult BMI categories for men and women. However, women and men with the same BMI can carry different amounts of body fat, and body composition changes with age. Older adults may lose muscle while their weight stays the same, so BMI can hide changes. A doctor can interpret your BMI alongside age, sex and health history.
BMI Limitations
- BMI does not separate fat from muscle, so athletes can read as overweight.
- It does not show where fat is stored. Abdominal fat carries more health risk.
- Some health organizations suggest different cut-offs for certain ethnic groups.
- It is not designed for pregnancy or for children and teens.
BMI vs Waist Size and Body Fat
Waist circumference adds useful context. Health agencies commonly cite a waist above 40 inches for men and 35 inches for women as a sign of higher risk. Body fat percentage, blood pressure, blood sugar and cholesterol also give a fuller picture than BMI alone.
BMI for Children and Teens
Ages 2 to 19 use BMI-for-age percentiles, not the adult categories above. Not sure about someone’s age? Check it with the Age Calculator, then use the CDC child and teen BMI calculator.
What to Do With Your Result
- Healthy range: keep up regular activity, balanced meals and sleep.
- Above or below the healthy range: discuss it with a doctor or registered dietitian before making big changes.
- Track weekly weight with the Average Calculator instead of reacting to daily changes.
- Adjust meal portions with the Recipe Scaler.
- Build a daily walk or workout habit with the Pomodoro Timer.
Frequently Asked Questions
What is a healthy BMI for adults?
For adults age 20 and older, the CDC defines 18.5 to 24.9 as the healthy weight range.
Is BMI the same for men and women?
Yes. The CDC uses the same adult categories for both, although body composition differs.
How do I calculate BMI in pounds and inches?
Divide weight in pounds by height in inches squared, then multiply by 703.
Is BMI accurate for athletes?
Not always. Muscle weighs more than fat, so muscular people can have a high BMI without excess body fat.
Is BMI a diagnosis?
No. It is a screening measure that should be reviewed with other health information.
Can I use this calculator for my child?
No. Children and teens need age- and sex-specific BMI percentiles.
Sources
Disclaimer: This calculator is for information and education only. It is not medical advice. Consult a qualified healthcare professional about your health.