BMI Calculator

Calculate your Body Mass Index instantly using our free BMI Calculator for men, women, teens & kids. Check if you are underweight, healthy, overweight, or obese by entering your height, weight, age & gender.

🧮 BMI Calculator

Free BMI Calculator For Adults, Teens and Children(Male and Female) – Check Your Body Mass Index Instantly with SEO Pheonix

One of the key steps to a healthy and disease-free life is maintaining a healthy body weight. The BMI Calculator, also known as the Body Mass Index Calculator, allows you to instantly determine whether your weight is healthy for your height and age. It's an easy yet effective tool that doctors, fitness professionals, and health professionals worldwide trust.

Use our BMI calculator for free to quickly check your body mass index — for men, women, adults, teenagers, and children. It's based on height (cm/ft) and weight (kg/lbs), and it tells you whether you are underweight, healthy, overweight, or obese.

What Is BMI (Body Mass Index)?

BMI (Body Mass Index) is a number that shows the relationship between your weight and height. It gives you an approximation of your body fat and indicates whether you're at a healthy weight for your body.

The formula for BMI is:

BMI = Weight (kg) ÷ [Height (m)]²

For instance, if you weigh 70 kg and have a height of 1.75 m,

→ BMI = 70 ÷ (1.75 × 1.75) = 22.86

As per the BMI chart, a BMI of 22.86 belongs to the "Healthy" range.

BMI Categories (For Adults)

The following is how BMI outcomes are read for adults:

BMI RangeCategoryHealth Meaning
Below 18.5UnderweightMay indicate malnutrition or low body fat
18.5 – 24.9Healthy WeightNormal and balanced body weight
25 – 29.9OverweightHigher risk of lifestyle diseases
30 and aboveObeseSignificantly increased health risk

BMI Formula – Metric and Imperial Units

It depends on your choice of measurement system, but calculate BMI online in either of two ways:

Metric Formula

BMI = weight (kg) / [height (m)]²

Imperial Formula

BMI = [weight (lbs) / height (in)²] × 703

Our BMI Calculator does both for you — pick between kg/cm or lbs/ft inputs for quick results.

Why Your BMI is Important for Your Health

Knowing your Body Mass Index is significant since it provides you with an idea of your general health and potential risks relating to being underweight or overweight.

Heart Health: An elevated BMI may raise the risk of heart disease and high blood pressure.

Risk of Diabetes: Overweight and obesity increase the risk of Type 2 diabetes.

Bone and Joint Well-being: Weight gain can lead to joint ache, arthritis, and movement problems.

Nutrition Insight: A low BMI may indicate under-nutrition, particularly in children or old individuals.

BMI is not a full diagnostic but it's an excellent starting point to assess your healthiness and lifestyle.

SEO Pheonix BMI Calculator for Everyone, Irrespective of Age

SEO Pheonix BMI Calculator is for all people — kids and elderly alike. Choose your gender (male/female), age category, and input your height and weight to receive individualized BMI results.

Adult BMI (18+)

Healthy BMI range: 18.5–24.9

Utilize this to monitor overall health and body composition.

Teen BMI (13–18)

During puberty, BMI varies by age and sex.

For adolescents, BMI percentile charts are employed instead of absolute values.

Child BMI (2–12)

Children's BMI is compared with percentile growth charts that take age and gender into consideration.

Assists in tracking healthy growth and nutrition.

Our calculator is used for everyone: BMI calculator female, BMI calculator male and BMI calculator for kids.

How to Use the SEO Pheonix BMI Calculator (Step-by-Step)

Our free BMI calculator kg steps tutorial: 

Choose Gender: Male or Female

Select Age Group: Adult, Teen, or Child

Enter Weight: in kilograms (kg) or pounds (lbs)

Enter Height: in centimeters (cm) or feet (ft/in)

Click “Calculate BMI”

Get an instant display of your BMI value and category (Underweight, Healthy, Overweight, or Obese)

Tip: Continuously update your BMI every few months to monitor your progress towards fitness targets.

Sample BMI Calculation Online

ExampleWeightHeightBMIResult
Adult Male70 kg175 cm22.9(BMI for men)Healthy
Adult Female85 kg160 cm33.2(BMI for women)Obese
Teen (Boy)50 kg165 cm18Underweight
Teen (Girl)55 kg160 cm22Healthy

How to Sustain a Healthy BMI

Maintaining and achieving a healthy BMI is not a matter of crash dieting — it's all about lasting lifestyle modifications.

Tips to Reduce BMI (If Overweight)

Eat a balanced, calorie-managed diet

Exercise for a minimum of 30–45 minutes a day

Hydrate with plenty of water and avoid sweetened beverages

Cut back on fast foods and packaged snacks

Get adequate sleep (7–8 hours at night)

How to Boost BMI (If Underweight)

Consume calorie-rich and protein-rich foods

Add healthy fats such as nuts, avocados, and olive oil

Do strength training exercises

Consume regular, small-sized meals throughout the day

Monitor your progress with the BMI Calculator from time to time

Limitations of BMI

While BMI is a common indicator, it has certain limitations:

❌ Fails to differentiate between muscle and fat

❌ May not be appropriate for athletes or bodybuilders

❌ Does not account for body shape, ethnicity, or gender differences

That’s why it’s important to use BMI as a general guideline, not a diagnostic measure. For a full health assessment, consider checking body fat percentage, waist circumference, or consulting a healthcare professional.

BMI and Health Risks

A high BMI is associated with several health concerns, including:

Type 2 diabetes

Hypertension (high blood pressure)

Heart diseases

Stroke

Sleep apnea

Osteoarthritis

Certain cancers

On the contrary, low BMI may cause:

Weakened immunity

Osteoporosis

Malnutrition

Fertility problems

Global BMI Statistics (WHO Data)

As per the World Health Organization (WHO):

More than 1.9 billion adults globally are overweight.

Over 650 million are obese.

Obesity among children has risen tenfold over the last 40 years.

This indicates the significance of tools such as BMI calculators in raising health awareness.

Conclusion: BMI Calculator By Age

Your body needs the correct balance — neither too heavy, nor too light. The BMI Calculator on SEO Pheonix assists you in determining that balance immediately. As an adult, teenager, or parent tracking your child's development, you can get precise information on your weight and health condition using this tool.

Begin today — get an instant check of your BMI and take the first step towards a healthier living!

Frequently Asked Questions: BMI Calculator Kg with Age

1. What is a normal BMI range?

A healthy or normal BMI for an adult is 18.5 to 24.9.

2. How frequently should I calculate my BMI?

It is best to calculate your BMI on BMI Calculator on SEO Pheonix every 3 to 6 months, particularly if you are on a diet or fitness regimen.

3. Is the calculation for BMI the same for both men and women?

Calculation is the same, but interpretation will vary marginally because of differences in body composition.

4. Do children also have the same BMI scale as adults?

No. Children and adolescents use age- and gender-adjusted percentile BMI charts.

5. My BMI is high but I'm highly muscular. What then?

In such a case, BMI may overestimate body fat. You can use a body fat calculator or get information from a fitness professional to get accurate measurements.