Check your Body Mass Index and Waist-to-Height Ratio instantly
Using your height of 175
Body Mass Index (BMI) is a simple calculation using a person's height and weight. It provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems.
BMI was developed by Belgian mathematician Adolphe Quetelet in the 1830s and remains one of the most widely used methods for assessing whether someone is at a healthy weight.
BMI divides adults into four main weight categories. Each category carries different health implications and may require different approaches to nutrition and lifestyle.
Being underweight can indicate nutritional deficiency, an eating disorder, or an underlying health condition. Risks include weakened immune system, fragile bones (osteoporosis), fertility problems, and feeling tired or lacking energy. If your BMI is below 18.5, consider consulting a healthcare provider to identify any underlying causes.
A normal BMI indicates that your weight is appropriate for your height and is associated with the lowest risk of weight-related health problems. Maintaining a normal BMI through balanced nutrition and regular physical activity supports overall health, energy levels, and longevity.
Being overweight increases the risk of developing conditions such as type 2 diabetes, high blood pressure, heart disease, and certain cancers. Even modest weight loss of 5-10% of body weight can significantly reduce these health risks. Lifestyle changes including improved diet and increased physical activity are typically recommended.
Obesity substantially increases the risk of serious health conditions including heart disease, stroke, type 2 diabetes, sleep apnea, and certain types of cancer. Obesity is further divided into classes: Class I (BMI 30-34.9), Class II (BMI 35-39.9), and Class III or severe obesity (BMI 40+). Treatment options may include lifestyle modifications, medication, or bariatric surgery.
| BMI Range | Category | Health Risk |
|---|---|---|
| Below 18.5 | Underweight | Increased risk of nutritional deficiency |
| 18.5 – 24.9 | Normal | Lowest risk of weight-related issues |
| 25.0 – 29.9 | Overweight | Moderate risk of health problems |
| 30.0 – 34.9 | Obese Class I | High risk of health conditions |
| 35.0 – 39.9 | Obese Class II | Very high risk of health conditions |
| 40.0 and above | Obese Class III | Extremely high risk of serious conditions |
BMI is calculated by dividing your weight by the square of your height. The formula differs slightly depending on the units you use:
Metric Formula
BMI = weight (kg) ÷ height² (m²)
Imperial Formula
BMI = 703 × weight (lbs) ÷ height² (in²)
Waist-to-Height Ratio (WHtR) is a measure of body fat distribution that compares your waist circumference to your height. Unlike BMI, which only considers total body mass, WHtR focuses on abdominal fat—a more dangerous type of fat associated with higher health risks.
Research has shown that WHtR is often a better predictor of cardiovascular disease, diabetes, and mortality risk than BMI alone. A simple rule of thumb: keep your waist circumference to less than half your height.
WHtR Formula
WHtR = waist circumference ÷ height
Your waist-to-height ratio indicates how your body fat is distributed and the associated health risks.
A ratio below 0.4 indicates very low abdominal fat. While this is generally positive, an extremely low ratio combined with underweight BMI may indicate insufficient nutrition or an eating disorder.
A healthy waist-to-height ratio between 0.4 and 0.5 indicates optimal fat distribution and is associated with the lowest risk of obesity-related health conditions. This is the target range for most adults.
A ratio between 0.5 and 0.6 suggests increased abdominal fat, which raises the risk of type 2 diabetes, cardiovascular disease, and metabolic syndrome. Lifestyle modifications including diet changes and increased physical activity are recommended.
A waist-to-height ratio of 0.6 or higher indicates high levels of abdominal fat and significantly elevated health risks. This level of central obesity is strongly associated with serious conditions including heart disease, stroke, and type 2 diabetes. Consultation with a healthcare provider is strongly recommended.
| WHtR Range | Category | Health Risk |
|---|---|---|
| Below 0.4 | Slim | Very low abdominal fat |
| 0.4 – 0.5 | Healthy | Optimal fat distribution |
| 0.5 – 0.6 | Increased Risk | Elevated risk of metabolic conditions |
| 0.6 and above | High Risk | Significantly elevated health risks |
Using both BMI and WHtR together provides a more complete picture of your health than either measurement alone. Here's why combining them matters:
For the best health assessment, aim for both a normal BMI (18.5–24.9) and a healthy WHtR (below 0.5).
While both BMI and WHtR are useful screening tools, they have limitations:
For a complete assessment of your health, consult with a healthcare professional who can consider additional factors like blood pressure, cholesterol, blood sugar, diet, physical activity level, and family history.
Accurate waist measurement is essential for a reliable waist-to-height ratio. Follow these steps:
For most people, this is roughly at the level of the belly button. Take measurements at the same time of day for consistency.
A healthy BMI for adults is between 18.5 and 24.9. This range is associated with the lowest risk of developing weight-related health conditions.
A healthy waist-to-height ratio is below 0.5, meaning your waist circumference should be less than half your height. Ratios between 0.4 and 0.5 are considered optimal for most adults.
Studies suggest WHtR may be a better predictor of cardiovascular disease and metabolic risks than BMI because it accounts for abdominal fat distribution. However, using both measurements together provides the most complete picture.
BMI is a general indicator and may not be accurate for athletes, elderly individuals, or pregnant women. It doesn't differentiate between muscle and fat mass.
BMI categories indicate your weight status: underweight (below 18.5), normal (18.5–24.9), overweight (25–29.9), and obese (30+). Each category carries different health implications and potential risks.
Checking your BMI and WHtR a few times per year is sufficient for most people. If you're actively trying to change your weight, monthly checks may help you track progress.
If your BMI is outside the normal range or your WHtR is above 0.5, consider consulting a healthcare provider. They can help determine if your measurements pose health risks and suggest appropriate lifestyle changes or treatments.