BMI 5'1" 170 lbs male

BMI is a way to discover if you are overweight, obese, underweight or normal. This calculator computes appropriately your BMI by using a "redefined overweight and obese BMI thresholds for different gender and age groups", a 2015[1] study, for people who are more than 16 years old male or female.

BMI Calculator - Feet, inches, lbs

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pounds (lbs)


Your BMI is 32.1, indicating your weight is in the overweight category for a 25 years old 5'1" heigh man.Your BMI Prime is 1.15. Please, see detailed information below.

Your relative position on the 25 years old man BMI scale:

suw = severely underweight, uw = underweight, ow = overweight

Detailed info about your BMI

Your Body Mass Index (BMI) is 32.1 Kg/m2. This means your weight is within the overweight range.

Your current BMI is greater than the recommended range of 18.5 to 28. To be within the right range for your height, your ideal weight should be between 97.9 and 148.2 pounds.

Being overweight increases your risk of developing coronary heart disease, as well as other health conditions such as diabetes. Keeping to a healthy weight will help you control your blood pressure and cholesterol levels. You lose weight if the amount of energy coming into your body is less than what is being used up by your body. Aim to exercise more and eat a healthy balanced diet. For individualised medical and dietary advice consult your GP and Dietitian.

What is BMI?

BMI is a person's weight in kilograms divided by his/her height in meters squared. For most people, BMI is a good predictor of health problems that are linked to excess weight. BMI is also known as Quetelet’s index.

Some research studies have shown that a weight loss of 1 to 2 pounds per week for six months can improve the health of overweight people. The goal of weight loss should be to improve health. You should avoid rapid weight loss, swings in weight, and improper dieting.

BMI is solely based on weight and height, so it may be a imprecise indicator (might come out as overweight) of body fat if someone has a large bone structure, athletic build or a large muscle mass. On the other hand, someone with a light bone structure might be considered of normal weight, even if they have excess body fat.

Although some factors like, bone structure, muscle mass ans body are not part of the equation when BMI is calculated, Body Mass Index can be helpful to set limits such as underweight, normal or obese, for individuals who lead a sedentary or "normal" life. Furthermore, our BMI calculator is better than the standard BMI calculator once it includes both sex and age into its algorithm.

How to calculate your BMI?

Here is the BMI formula in the English (Avoirdupois) system where weight is in pounds, and height is in inches:

BMI = 703 x (weight/(height)2)

For example:

If your height is 61 inches and you weigh 170 pounds, your BMI is

BMI = 703 x (170/612), or

BMI = 703 x (170/3721), or

BMI = 703 x 0.045686643375437

Finally, BMI = 32.1 kg/m2 (rounded).

What is BMI Prime?

BMI Prime[3] (abbreviated BMI’) is an index of total body fat content. It is a simple modification of the familiar Body Mass Index (BMI) system.

BMI Prime is defined as the ratio of a person’s Actual Weight (or Mass) to his Upper Weight (or Mass) Limit of the “healthy weight” range. Here is the BMI Prime formula:

BMI' = Actual Weight/Upper Weight Limit

Note that, in our BMI calculator, the 'Upper Weight Limit' depends on age and sex, so it is not fixed as in other calculators.

Standard BMI Chart

This table defines BMI ranges (Categories). This standard is still widely used nowadays mainly to compare populations in health related studies.

BMI Weight Status
9.0 to 18.5 underweight
18.6 to 24.9 normal
25.0 29.9 overweight
30.0 and Above Obese

Modified BMI Chart

The standard BMI, as defined, for example, by the World Health Organization, WHO and USDA (United States Department of Agriculture), has been frequently criticised as having various deficiencies as a measure of body fat. But this 2015 study published by the The National Center for Biotechnology Information (NCBI) made some adjustments on BMI limits to reflect the changes in body composition that occur with age like: reduced muscle mass and increased adiposity. This means that our BMI is not the same across different age groups and gender because these factors are included in our algorithm. The BMI table below, combined with the standard (WHO) BMI table, are used by our BMI Calculator to redefine the BMI classes limits.

Redefined overweight and obese BMI thresholds table

Age (years)OverweightObeseOverweightObese

Sample Calculations

Important note on BMI web tools

This calculator is not meant to serve as a source of clinical guidance. It does not provide medical advice. BMI is only an indicator of body fatness. It also doesn't apply if you have an athletic/muscular build because muscle weighs more than fat. Be carefull. Do not use this tool calculating BMI for children Do not take any important decision about your health based on this or on any other web tool. Any questions about weight loss or changes to your diet should be discussed with your nutritionist or medical adviser for a more personalized estimation.

BMI Calculator

BMI Calculator

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  1. The need to redefine age- and gender-specific overweight and obese body mass index cutoff points (Retrieved AUgust 31st 2016)
  2. Body Mass Index and Health - CNPP (Center for Nutrition Policy and Promotion) / USDA (United States Department of Agriculture) (Retrieved AUgust 31st 2016)
  3. BMI Prime

Sample BMI calculations - feet, inches and pounds