BMI is a way to determine if a person is underweight, normal weight, overweight or obese.

Body mass index (BMI) is a measurement of body fat based on height and weight. The formula for calculating BMI is given in Table 1 or you can use the body mass index calculator below.

Maintaining a healthy weight offers the following health benefits:

- Reduced risk of heart disease and certain cancers
- Better sleep quality
- Fewer muscle and joint pains
- Reduced risk of high blood pressure and diabetes
- Better regulation of bodily fluids
- Reduced burden on the heart and circulatory system
- High energy and ability to complete the desired activities
- Reduced cholesterol levels
- Reduced risk of gallbladder disease

**Table 1. The Formula for Calculating BMI**

**Measurement Units**

**Formula and Calculation**Kilograms and meters (or centimeters)

Formula: weight (kg) / height (m)^{2}

The formula for BMI is weight in kilograms divided by height in meters squared. If height has been measured in centimeters, divide by 100 to convert this to meters.

Pounds and inchesFormula: 703 x weight (lbs) / height (in)^{2}

When using English measurements, pounds should be divided by inches squared. This should then be multiplied by 703 to convert from lbs/inches^{2} to kg/m^{2}.

Example: If a person weighs 65 kg and the person’s height is 165 cm (1.65 m), the BMI is calculated as 65 ÷ (1.65)2 = 23.87 kg/m2, which means that the person has a BMI of 23.87 kg/m2 and is considered to have a healthy weight.

When calculating in pounds and inches, if a person weighs 120 lbs and the person’s height is 5 feet 6 inches (66 inches), the BMI is calculated as 703 x 120/(66)2 = 19.3 kg/m2, which means that the person has a BMI of 19.3 kg/m2 and is considered to have a healthy weight.

### What is the body mass index (BMI)?

Body mass index (BMI) is a person’s weight in kilograms divided by the square of height in meters. It indicates the amount of body fat.

BMI is the most inexpensive screening tool to measure body fat. Although it does not directly measure body fat, it can be correlated with a more direct measure of body fat.

The various categories of BMI include

- BMI values less than 18.5 kg/m2 are considered underweight
- BMI values between 18.5 kg/m2 to 24.9 kg/m2 are healthy
- BMI values between 25 kg/m2 to 30 kg/m2 are overweight
- BMI values greater than 40 kg/m2 are considered obese

### What is the ideal BMI?

The ideal weight has been mentioned in Table 2.

**Table 2. Ideal Weight in lbs According to Height**

**Height**

**Minimal risk**

(BMI under 25 kg/m

(BMI under 25 kg/m

^{2})**Moderate risk
(BMI 25–29.9 kg/m ^{2})
Overweight**

**High risk
(BMI 30 kg/m ^{2} and above)
Obese**

118 or less

119–142

143 or more

123 or less

124–147

148 or more

127 or less

128–152

153 or more

131 or less

132–157

158 or more

135 or less

136–163

164 or more

140 or less

141–168

169 or more

144 or less

145–173

174 or more

149 or less

150–179

180 or more

154 or less

155–185

186 or more

158 or less

159–190

191 or more

163 or less

164–196

197 or more

168 or less

169–202

203 or more

173 or less

174–208

209 or more

178 or less

179–214

215 or more

183 or less

184–220

221 or more

188 or less

189–226

227 or more

193 or less

194–232

233 or more

199 or less

200–239

240 or more

204 or less

205–245

246 or more