Your Ideal Body Weight

What is my ideal body weight and how do I calculate it?

FIGURING OUT YOUR IDEAL WEIGHT

When someone declares that they want to "lose weight", what they often mean is that they want to lose fat. Many people will pick a weight target simply buy picking a number ("I want to lose 10 pounds" or "I want to weight around 115 pounds"). While this method may be easy, it's also the wrong way to go about weight loss. Body fat measurements and the measuring tape are recognized as superior methods for measuring "weight loss" and figuring out your target weight.

In this section, we'll teach you why simply picking a weight is the wrong way to go, and show you how to properly calculate your ideal weight loss target!

Body Fat Guide

Your body fat percentage is simply the percentage of fat your body contains. If you are 150 pounds and 10% fat, it means that your body consists of 15 pounds fat and 135 pounds lean body mass (bone, muscle, organ tissue, blood and everything else).

In the chart below, you will see (in red) that a certain amount of fat is essential to bodily functions. In green, you will find ideal body fat percentages for a physcially fit person.

Classification Women (%) Men (%)
Essential Fat 10-12% 2-4%
Athletes 14-20% 6-13%
Physically Fit 21-24% 14-17%
Acceptable 25-31% 18-25%
Obese 32% plus 25% plus

Your probably wondering how to calculate your body fat %, we'll get to that below. But first, let's learn why just "picking a weight" not such a good way to start.

THE WRONG METHOD (picking a weight)

Before we learn "The Good", we need to understand "The Bad".

Let's say there is a 130lb woman with 23% body fat, and her goal is to "lose 20 pounds". It may sound like a solid goal, but the goal is actualy un-realistic.

From the chart above, we know that the ideal body fat percentage for a physically fit woman is 21%. We also know that 10-12% of that fat is "Essential Body Fat" required to maintain LIFE and reproductive functions. So what will happen in this scenario if she simply drops 20lbs of weight?

  1. First, let's figure out how many lbs of fat she has by multiplying her weight by her body fat %:
    130lb x 0.23 fat = 30lbs of body fat

  2. This means we now know that her "Lean Body Mass" (bones, organs, etc) is:
    130lb - 30lbs fat = 100lbs lean body mass

  3. So if she simply loses 20lbs, what is she left with?
    130lb - 20lbs = 110lbs

  4. Finally, lets see what her new body fat % is:
    100 (lean mass) / 110 (total weight) * 100 = 9% body fat

As you can see, this % does not even meet the Essential Body Fat required for a female. This would leave her at dangeriously low body fat levels.

THE RIGHT METHOD (body fat targeting)

So what's a better method than the crap-shoot above? We call it "Body Fat Targeting". Once you know your body fat %, you can begin targeting new body fat percentages.

In the example above, the woman should have set her goal at 21% body fat (or 18% if she would like an athletic type body). Once she's chosen a safe body fat % as her target, a few simple calculations will tell her exactly what she needs to lose to get there.

  1. First, let's figure out how many lbs of fat she has by multiplying her weight by her body fat %:
    130lb x 0.23 fat = 30lbs of body fat

  2. This means we now know that her "Lean Body Mass" (bones, organs, etc) is:
    130lb - 30lbs fat = 100lbs lean body mass

  3. Now we will simply add our target of 21% to her lean body mass to get our target weight:
    100lbs (lean mass) * 0.21 (body fat) + 100lbs (lean mass) = 121lbs

By following this, we now know that this persons ideal weight is 121lbs. To get there, she only has to burn off 9lbs! With a standard workout regime, she should be able to drop 1.5lbs per week; so, a good weight challenge should be 9lbs in 6 weeks!

HOW DO I CALCULATE MY BODY FAT %

Luckily we've made it easy to get a proper estimate! Simply make sure you've updated the measurements in your profile and we'll do all the number crunching for you!

Males:
• Keep your WAIST, NECK & HEIGHT measurements updated.

Females:
• Keep your WAIST, HIP, NECK & HEIGHT measurements updated.

If your looking for the actual formulas we use, here they are:

Male Formula (measurements in cm):
BF% = 495 / (1.0324 - 0.19077 * Log10(WAIST - NECK) + 0.15456 * Log10(HEIGHT)) - 450

Female Formula (measurements in cm):
BF% = 495 / (1.29579 - 0.35004 * Log10(WAIST + HIP - NECK) + 0.22100 * Log10(HEIGHT)) - 450

Update Your Measurements