BMI Calculator - Free Body Mass Index Calculator
Calculate your Body Mass Index (BMI) instantly with our free online calculator. Check your BMI, view the BMI chart, and find your healthy weight range.
What is BMI (Body Mass Index)?
Body Mass Index (BMI) is a widely-used screening tool that estimates body fat based on your height and weight. This free online BMI calculator helps you determine if you're at a healthy weight, underweight, overweight, or obese according to World Health Organization (WHO) standards.
BMI Formula - How to Calculate BMI
Our BMI calculator uses the standard BMI formula to compute your body mass index:
BMI Formula (Metric):
BMI = weight (kg) / [height (m)]²
BMI Formula (Imperial):
BMI = [weight (lbs) × 703] / [height (inches)]²
BMI Chart - Understanding Your BMI Scale
The BMI scale categorizes body mass index into different ranges. Use this BMI chart to understand what your BMI number means:
Below healthy weight range - may indicate nutritional deficiency
Healthy BMI range - optimal for most adults
Above healthy weight - increased health risk
Obesity - significant health concerns
Severe obesity - serious health risks
Morbid obesity - very high health risks
BMI Calculator for Men vs Women
While the BMI formula is the same for both men and women, interpretation can vary slightly:
BMI for Men
Men typically have more muscle mass, which can result in higher BMI without excess fat. A BMI calculator for men should be interpreted alongside body composition.
BMI for Women
Women naturally have higher body fat percentage. A BMI calculator for women should account for factors like pregnancy, menopause, and hormonal changes.
How to Use Your BMI Results
After using our BMI calculator online, here's what to do with your results:
- Check your BMI category: See where you fall on the BMI scale
- Find your healthy weight range: Use your height to determine ideal weight
- Set realistic goals: If outside healthy BMI range, plan gradual changes
- Monitor progress: Regularly check BMI when working toward health goals
- Consult professionals: Discuss BMI results with healthcare providers
Limitations of BMI Calculator
While a BMI calculator is a useful screening tool, it has limitations:
❌ Not Accurate For:
- Athletes and bodybuilders
- Pregnant women
- Elderly individuals
- Growing children
- People with high muscle mass
✓ Good Screening Tool For:
- General adult population
- Tracking weight changes
- Initial health assessment
- Population health studies
- Quick health checks
⚠️ Important Note
BMI is a screening tool, not a diagnostic tool. It doesn't measure body fat directly or account for muscle mass, bone density, or fat distribution. For comprehensive health assessment, consult a healthcare professional who can evaluate BMI alongside other health markers.
BMI and Health Risks
Research shows that BMI correlates with various health risks:
Why Use Our Free BMI Calculator?
- ✓100% Free: No registration, no payment - calculate your BMI instantly online
- ✓Accurate BMI Formula: Uses the standard WHO BMI calculation method
- ✓Instant Results: Check your BMI in seconds with our online calculator
- ✓BMI Chart Included: Visual BMI scale to understand your category
- ✓Healthy Weight Range: Automatically calculates ideal weight for your height
- ✓Imperial & Metric: Calculate BMI in pounds/feet or kilograms/centimeters
Frequently Asked Questions About BMI
What is a good BMI?
A healthy or "good" BMI for adults is between 18.5 and 24.9. This range is associated with the lowest health risks for the general population. However, optimal BMI can vary based on age, ethnicity, and individual health factors.
How accurate is the BMI calculator?
The BMI calculation itself is mathematically accurate, but its interpretation has limitations. BMI doesn't distinguish between muscle and fat, so athletes may have "high" BMI despite low body fat. Use BMI as one tool among many for assessing health.
Can I use BMI calculator if I'm pregnant?
Standard BMI calculators are not appropriate during pregnancy. Weight gain during pregnancy is normal and necessary. Pregnant women should consult their healthcare provider about healthy weight ranges throughout pregnancy.
What's the difference between BMI and body fat percentage?
BMI is a ratio of weight to height, while body fat percentage measures actual fat tissue. Body fat percentage is more accurate but requires special equipment. BMI is easier to calculate and works well for screening large populations.