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BMI Calculator

Calculate your Body Mass Index (BMI) and discover if you're at a healthy weight. Get instant results with personalized health recommendations.

Weight (kg)

Height (cm)

Your BMI Category

Category: -

Healthy Weight Range: -

Weight to Lose/Gain: -

About This BMI Calculator

Our free BMI calculator helps you determine your Body Mass Index, a widely-used screening tool that measures body fat based on your height and weight. Understanding your BMI is the first step in assessing whether you're at a healthy weight. For a more detailed body composition analysis, try our body fat calculator or determine your ideal weight with our ideal weight calculator.

The calculator provides instant results showing your BMI value, weight category (underweight, normal, overweight, or obese), and personalized recommendations to help you achieve or maintain a healthy weight. To support your fitness goals, consider using our calorie calculator to track your daily caloric needs or our macro calculator for balanced nutrition planning.

How to Use the BMI Calculator

Choose Your Unit System: Select either Metric (kg, cm) or Imperial (lb, ft/in) based on your preference.
Enter Your Weight: Input your current body weight in kilograms or pounds.
Enter Your Height: Provide your height in centimeters, or feet and inches.
Click Calculate: Get instant results showing your BMI and health category.

Understanding Your BMI Results

BMI Value: Your calculated Body Mass Index number. This is the ratio of your weight to your height squared.

Category: Shows whether you're underweight (BMI < 18.5), normal weight (18.5-24.9), overweight (25-29.9), or obese (≥ 30).

Healthy Weight Range: The recommended weight range for your height based on a healthy BMI of 18.5-24.9.

Weight to Lose/Gain: If applicable, shows how much weight change would bring you into the healthy BMI range.

BMI Categories and Health Recommendations

Underweight (BMI < 18.5)

Being underweight can indicate malnutrition, eating disorders, or other health issues. If your BMI is below 18.5:

Consult a Healthcare Provider: Identify any underlying causes of low weight.
Increase Caloric Intake: Focus on nutrient-dense foods rather than empty calories.
Strength Training: Build muscle mass through resistance exercises.
Monitor Health: Watch for symptoms like fatigue, weakened immunity, or irregular periods.

Normal Weight (BMI 18.5-24.9)

Congratulations! You're in the healthy weight range. To maintain your weight:

Balanced Diet: Continue eating a variety of nutritious foods.
Stay Active: Aim for 150+ minutes of moderate exercise weekly.
Regular Check-ups: Monitor your health with routine medical visits.
Consistent Habits: Maintain the healthy lifestyle choices that got you here.

Overweight (BMI 25-29.9)

Being overweight increases risk of various health conditions. Consider these steps:

Gradual Weight Loss: Aim for 1-2 pounds per week for sustainable results.
Portion Control: Reduce serving sizes and limit processed foods.
Increase Activity: Work up to 200-300 minutes of exercise weekly.
Track Progress: Monitor calories and set realistic, achievable goals.
Professional Guidance: Consult a dietitian for personalized advice.

Obese (BMI ≥ 30)

Obesity significantly increases health risks including heart disease, diabetes, and certain cancers:

Medical Consultation: Seek professional medical advice immediately.
Comprehensive Program: Consider a medically-supervised weight management program.
Health Screening: Get tested for diabetes, high blood pressure, and cholesterol.
Explore Options: Discuss lifestyle changes, medication, or surgical interventions.
Long-term Focus: Prioritize sustainable changes over quick fixes.

Frequently Asked Questions

What is BMI?

BMI (Body Mass Index) is a measure of body fat based on height and weight. It's calculated by dividing weight in kilograms by height in meters squared (kg/m²). BMI provides a quick estimate of whether you're at a healthy weight for your height, though it has some limitations.

What is a healthy BMI range?

A healthy BMI range for adults is 18.5-24.9. Below 18.5 is considered underweight, 25-29.9 is overweight, and 30 or above is obese. These ranges are associated with different health risks, though individual circumstances may vary.

How do I calculate my BMI?

BMI = weight (kg) ÷ [height (m)]². In imperial units: BMI = (weight in pounds × 703) ÷ [height in inches]². Our calculator does this automatically - just enter your weight and height, and we'll provide your BMI instantly.

Is BMI accurate for everyone?

BMI is a useful screening tool but has limitations. It doesn't distinguish between muscle and fat, so athletes and bodybuilders may have high BMI despite being very healthy. It also doesn't account for age-related muscle loss, gender differences in body composition, or ethnic variations. Consider BMI as one indicator among many.

What should I do if my BMI is unhealthy?

Consult a healthcare provider for personalized advice based on your overall health, not just BMI. Generally, focus on: balanced nutrition with whole foods, regular physical activity (both cardio and strength training), adequate sleep (7-9 hours), stress management, and sustainable lifestyle changes rather than crash diets or quick fixes.

How often should I check my BMI?

For general health monitoring, checking BMI monthly or quarterly is sufficient. If you're actively trying to lose or gain weight, weekly checks can help track progress. Remember that weight fluctuates naturally, so focus on trends over time rather than daily changes.

Can children use this BMI calculator?

This calculator is designed for adults aged 20 and over. Children and teenagers should use BMI-for-age percentile charts instead, as their body composition changes as they grow. These charts account for age and sex. Always consult a pediatrician for accurate assessment of children's weight.

What's better than BMI for measuring health?

Alternatives include: waist circumference (better indicator of abdominal fat), waist-to-hip ratio (shows fat distribution), body fat percentage (direct measure of fat vs. lean mass), and DEXA scans (most accurate body composition analysis). However, BMI remains useful as a quick, free screening tool.