Are you trying to estimate how much weight you need to lose? Well, in order to know that, you need to know how much body fat you should have and how much you actually should have. This body fat calculator will tell you the amount of fat you have right now.

On the other hand, the information given below might help you figure out how much weight you need to lose. The amount of body fat you have is calculated on the basis of your height, weight and waist size. While your height cannot change anymore, your weight and waist can.

So, let’s see how our body fat is related to our weight.

**What is Body Fat Percentage and How is it Calculated?**

After digesting the food that you consume, your body stores some of the fat that is used for energy and protecting your body. This is the body fat that we’ll be calculating in percentage form.

Now, before we go on to the technical details, there’s one thing you should know – the bodies of males and females work differently. Hence, the body fat percentage will differ slightly for males and females.

Now, there are plenty of formulas by which you can actually calculate the percentage of body fat in a male or female. Considering the difference in their bodies, the formula will also differ for both. By giving your height, waist and weight, here’s how your body fat percentage can be calculated:

**The Height to Waist Formula:**

Body Fat Percentage in Men = 64 – (20 x height/waist)

Body Fat Percentage in Women = 76 – (20 x height/waist)

**Estimating Body Fat Percentage Using Total Weight:**

Body Fat Percentage in Men = (weight x 1.082) + 94.42

Body Fat Percentage in Women = (weight x 0.732) + 8.987

**Ideal Body Fat Percentage for Men and Women**

Age Group | Percentage Range for Men | Percentage Range for Women |

20-40 | 8-19 | 21-33 |

41-60 | 11-22 | 23-35 |

61-79 | 13-25 | 24-36 |

**Body Mass Index, Lean Body Mass and Fat Body Mass**

**Body mass index** is considered to be a better indication of whether or not you’re overweight. This is determined by calculating the ratio between your weight and height. In other words, you may say that it is your body weight with respect to your height.

When calculating in kgs and metres:

BMI = weight/height

When calculating in pounds and inches:

BMI = (weight/height^{2})^{ }x 703

Here’s how you’ll know through your BMI whether you’re underweight, fit or overweight:

Less than 18.5: Underweight

Between 18.5-24.9: Fit

Between 25-29.9: Overweight

Above 30: Obese

**Fat body mass **is the actual amount of fat that is there in your body. This is derived from your body fat percentage.

**Lean body mass** is the difference between your total body weight and body fat. This calculation can only be done after we have your fat body mass. Here’s how we calculate it:

Fat Body Mass = total body weight (in lbs) x body fat percentage

Lean Body mass = total body weight – amount of body fat