BMI Calculator (Male & Female)

Use our free BMI calculator for male and female users to find your Body Mass Index (BMI full form). Whether you need a BMI calculator kg with age or a BMI calculator in kg and feet, this tool instantly calculates your score. Learn how to calculate BMI and find your ideal BMI below. No signup required.

How to Use the BMI Calculator

Calculating your Body Mass Index (BMI) is quick and easy. Follow these simple steps:

• 1
  Choose Your Units: Select your preferred measurement system (Metric or US Units) from the dropdown menu. You can use this as a BMI calculator in kg and feet by selecting the appropriate units.
• 2
  Enter Age & Gender: Input your age and select your gender (male or female). This helps determine the correct percentile category if the subject is under 20 years old.
• 3
  Input Height: Enter your height in centimeters, or in feet and inches (depending on your selected unit system).
• 4
  Input Weight: Enter your weight in kilograms or pounds.
• 5
  Calculate: Click the "Calculate BMI" button. Your BMI, BMI Prime, and Ponderal Index will be displayed instantly, along with a visual gauge showing where you fall on the scale.

What is BMI?

The BMI full form is Body Mass Index. It is a numerical value of your weight in relation to your height. It is a simple, inexpensive, and noninvasive screening method used to identify possible weight problems for adults. However, BMI is not a diagnostic tool. For example, a person may have a high BMI, but to determine if excess weight is a health risk, a healthcare provider would need to perform further assessments.

How to Calculate BMI (Formula)

If you want to know how to calculate BMI manually, you use the following formulas based on your BMI unit system:

BMI Prime

BMI Prime is a ratio of a person's actual BMI to their upper limit "healthy" BMI (usually defined as 25).

A BMI Prime less than 0.74 indicates underweight, between 0.74 and 1.0 is optimal, and greater than 1.0 indicates overweight.

Ponderal Index

The Ponderal Index (PI) is similar to BMI but uses the cube of the height instead of the square. It is often used for more extreme heights or heights where BMI might be inaccurate.

BMI Table for Adults

BMI Table for Children and Teens (Age 2-20)

BMI is interpreted differently for children and teens. It is age- and sex-specific and is referred to as BMI-for-age. A child's weight status is determined using an age- and sex-specific percentile.

BMI Charts for Children and Teens (Reference)

Below are simplified reference points for BMI percentiles based on CDC growth charts. Use these to locate the calculated BMI on the chart corresponding to the child's age and gender.

Health Risks

Limitations of BMI

While BMI is a useful screening tool, it has limitations:

• Overestimates body fat: In athletes and individuals with high muscle mass. For a more accurate measurement, we recommend using our body fat calculator or navy body fat calculator.
• Underestimates body fat: In the elderly or individuals who have lost muscle mass.
• Does not measure fat distribution: It does not distinguish between visceral fat (belly fat) and subcutaneous fat.
• Ethnicity variations: Some ethnic groups may have different health risks at the same BMI (e.g., Asians may have higher risks at lower BMIs).

Frequently Asked Questions (FAQ)

What is the BMI full form?

The BMI full form is Body Mass Index. It is a numerical value of your weight in relation to your height, commonly used to screen for weight categories that may lead to health problems.

How to calculate BMI?

To calculate BMI, use the formula: weight (kg) / [height (m)]². If you are using US units, the formula is: 703 x weight (lbs) / [height (in)]². However, it is much easier to use our free online BMI calculator above which does the math for you instantly.

Can I use this as a BMI calculator kg with age?

Yes. This calculator supports Metric units (kg and cm). You can also input your age and gender. While BMI is calculated the same for adults of all ages, inputting age is necessary to determine the correct percentile category if the subject is under 20 years old.

Does this BMI calculator support kg and feet?

Yes, you can mix and match or use standard combinations. Use the "Unit System" dropdown to select Metric (kg, cm) or US Units (lbs, ft+in). The calculator will automatically adapt the inputs for a BMI calculator in kg and feet.

What is the ideal BMI for male and female adults?

The ideal BMI for both male and female adults is generally considered to be between 18.5 and 24.9. This range is classified as a "Healthy Weight". A BMI below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is obese.

What is the BMI unit?

BMI is a dimensionless number, meaning it technically has no physical unit. It is expressed as kg/m² (kilograms per square meter) in the metric system, but the final BMI value itself is just a number (e.g., 22.5).

Is BMI accurate for athletes or bodybuilders?

BMI has limitations. Because it only calculates weight relative to height, it does not distinguish between muscle mass and fat mass. Highly muscular individuals may register as "overweight" or "obese" on the BMI scale despite having very low body fat. For precise body composition, a body fat calculator is recommended. To understand why, read our complete guide on BMI vs. Body Fat Percentage.

Does this calculator store my health data?

No. Your privacy is our priority. All calculations happen directly in your web browser. We do not collect, save, or transmit your height, weight, or any other personal information to our servers.