Free BMI Calculator - Calculate Your Body Mass Index
Calculate your Body Mass Index (BMI) instantly with our free online calculator. Determine if you're at a healthy weight using metric (kg/cm) or imperial (lbs/inches) units. Get your BMI score, category, and ideal weight range in seconds.
Male
Female
Your Results
70 kg
Weight
175 cm
Height
26
Age
male
Gender
Healthy Weight Range
56.7 kg - 76.3 kg
For your height of 175 cm
Understanding BMI Categories and Ranges
BMI categories help classify your weight status. Here's what each BMI range means for your health:
Underweight: BMI Less than 18.5
A BMI below 18.5 may indicate malnutrition, eating disorders, or other health problems. Consult a healthcare provider if you're underweight.
Normal Weight: BMI 18.5 - 24.9
A BMI between 18.5 and 24.9 indicates a healthy weight for your height. This is the ideal BMI range associated with the lowest health risks.
Overweight: BMI 25 - 29.9
A BMI between 25 and 29.9 indicates you're overweight. This may increase your risk of cardiovascular disease, diabetes, and other health conditions.
Obese: BMI 30 or Greater
A BMI of 30 or higher indicates obesity, which significantly increases health risks including heart disease, stroke, type 2 diabetes, and certain cancers. Medical consultation is recommended.
How to Calculate BMI - Formula and Examples
Body Mass Index is calculated using your weight and height with different formulas for metric and imperial units:
BMI Formula (Metric Units - kg and meters):
BMI = weight (kg) / (height (m))²
Example: If you weigh 70 kg and are 1.75 m tall: BMI = 70 / (1.75)² = 22.86
BMI Formula (Imperial Units - pounds and inches):
BMI = (weight (lbs) / (height (inches))²) × 703
Example: If you weigh 154 lbs and are 69 inches tall: BMI = (154 / 69²) × 703 = 22.75
BMI Calculator Limitations and Considerations
While BMI is a useful screening tool, it's important to understand its limitations:
- •Doesn't measure body composition: BMI doesn't distinguish between muscle mass and fat mass, which can lead to inaccurate results for muscular individuals
- •Not accurate for athletes: Athletes with high muscle mass may have a high BMI despite having low body fat
- •Age and gender differences: BMI doesn't account for natural variations in body composition by age, gender, or ethnicity
- •Not for pregnant women: BMI calculations are not suitable during pregnancy due to natural weight changes
- •Children require different standards: BMI for children and teens uses age and sex-specific percentiles
- •Screening tool only: BMI should be used as an initial screening tool, not a diagnostic tool for health conditions
Important: Always consult with a healthcare professional or registered dietitian for personalized health advice and accurate body composition assessment. They can provide a comprehensive evaluation using additional measures like waist circumference, body fat percentage, and overall health markers.
Frequently Asked Questions About BMI
What is a good BMI for my age?
For adults over 20, a BMI between 18.5 and 24.9 is generally considered healthy regardless of age. However, some research suggests slightly higher BMI values may be acceptable for older adults. Always consult your doctor for personalized recommendations.
How often should I calculate my BMI?
It's recommended to check your BMI every 3-6 months if you're monitoring your weight. More frequent calculations may be helpful if you're actively trying to lose or gain weight under medical supervision.
Can BMI predict health problems?
BMI is correlated with health risks but doesn't predict individual health outcomes. People with higher BMI have increased risk of conditions like heart disease, diabetes, and hypertension, but other factors like diet, exercise, genetics, and overall health also play crucial roles.