This BMI calculator, provided by Hesapstan, uses your weight and height to estimate your body mass index. BMI is commonly used in Turkey and internationally as a quick adult screening indicator, but it is not a diagnosis and does not directly measure body fat.
What is BMI?
BMI, or body mass index, is a simple number calculated from weight and height. It is often used to describe whether an adult's weight is generally below, within, or above a standard range for their height.
BMI can help answer basic questions such as:
- What is my BMI value?
- Which adult BMI category does my result fall into?
- What is the approximate healthy weight range for my height?
BMI does not directly measure body fat. It also does not account for muscle mass, waist size, age, sex, pregnancy, training level, or medical history.
What does this calculator calculate?
The calculator asks for:
- Weight in kilograms
- Height in centimeters
It then shows the BMI value, BMI category, approximate healthy weight range for the entered height, how the entered weight compares with that range, a brief interpretation, and a caution about BMI limitations.
The current formula rejects unrealistic entries instead of showing a normal-looking result. In the current implementation, weight is expected to be between 20 and 350 kg, and height between 100 and 250 cm.
BMI formula
BMI is calculated with this formula: BMI = weight / height². Weight is entered in kilograms. Height is converted from centimeters to meters before calculation.
- Weight: 70 kg
- Height: 175 cm = 1.75 m
- Calculation: 70 / (1.75 × 1.75)
- Result: 22.9
For adults, this result falls within the general healthy BMI range.
How BMI categories are interpreted
This calculator uses common adult BMI ranges:
- Below 18.5: underweight
- 18.5 to 24.9: healthy weight
- 25.0 to 29.9: overweight
- 30.0 to 34.9: obesity class 1
- 35.0 to 39.9: obesity class 2
- 40 or above: obesity class 3
These categories are useful for screening, but they are not a full health assessment. Waist measurement, body fat percentage, muscle mass, age, and medical history can all change how the result should be understood.
How the healthy weight range is calculated
The calculator estimates the weight range that would put the entered height between BMI 18.5 and 24.9.
- For a height of 175 cm, the lower end is 18.5 × 1.75² = about 56.7 kg
- The upper end is 24.9 × 1.75² = about 76.3 kg
- If the user enters 70 kg and 175 cm, the calculator shows that the weight is within this range.
This is not a personal target weight; it is only a general BMI-based adult range.
When BMI is not enough
BMI can be misleading when used alone. Be careful especially in these cases:
- Children and teenagers: adult BMI cut-offs are not the right method.
- Pregnancy: weight assessment during pregnancy follows different guidance.
- Very muscular athletes: high muscle mass can raise BMI.
- Older adults: body composition and muscle loss can affect interpretation.
- Medical conditions: some conditions affect weight, fluid balance, or body composition.
BMI is a useful starting point, not a final answer.
Common mistakes
- Entering height in meters instead of centimeters.
- Treating BMI as a medical diagnosis.
- Ignoring waist size or body fat percentage.
- Using adult BMI categories for children or pregnancy.
- Treating the healthy range as an exact personal target.
How to use the result
Use the BMI result as a first screening indicator. If your result is outside the general healthy range, it may be useful to look at other indicators such as waist-to-hip ratio, body fat percentage, daily calorie needs, activity level, and overall health.
Do not use this calculator alone for medical decisions, treatment, rapid weight-loss plans, pregnancy decisions, or disease-risk assessment. A doctor, dietitian, or qualified health professional can give a personal evaluation.
Frequently Asked Questions
What is a healthy BMI for adults?
For adults, 18.5 to 24.9 is commonly used as the healthy BMI range. It is still only a general indicator and does not fully describe health or body fat.
Is BMI a diagnosis of obesity?
No. BMI is a screening indicator, not a diagnosis. A full assessment may include waist measurement, body composition, medical history, and professional evaluation.
Can this BMI calculator be used for children?
This calculator uses adult BMI ranges. Children and teenagers need age- and sex-specific percentile-based assessment.
Why can BMI be high in athletes?
BMI does not separate muscle from fat. A muscular person may have a high BMI without necessarily having high body fat.
Is the healthy weight range my ideal weight?
No. It is a general range based on BMI 18.5–24.9 for the entered height. Personal weight goals depend on body composition, health, activity, and professional advice when needed.