# Body Fat Calculator

**How
to Calculate Your Bodyfat Percentage**

**Click here for a nice online calculator **

**Hugo Rivera,** writes, "One
thing we engineers love are formulas and these I have found to
be pretty accurate to calculate bodyfat. They are within +/- 3%
of the real value. All you will need is a tape measure, a piece
of paper, pencil or pen and a calculator."

*A common response in our forum is that this is too complicated. Many of us estimate progress by the mirror, the belt or the tightness of the button on the jeans.*

Here's a **lean body mass calculator** from the National Institute of Health.

**Meanwhile, Hugo offers up the following formula: **

**Click
here to use the formula in an Excel spreadsheet**

(You'll
need the formula notes below for measurement descriptions)

**For
Men:**

Before
you use the formulas, there are two measurements that are required:

Measurement
1: **Bodyweight**

Measurement
2: **Waist Girth (measured at the umbilicus)**

**Procedure:**

**1)** Multiply your bodyweight by 1.082. Add
the result to 94.42. Once your calculation
is complete, save the number. à (Bodyweight
x 1.082) + 94.42=Result 1

**2)** Multiply your waist girth by 4.15. Once
you get this result, subtract it from the
number obtained in step 1 (ie: Step 1 result-Step
2 result). The result obtained after the subtraction is done is your
lean bodyweight (your weight if you had no fat in your body at all). à Result
1 - (Waist Girth x 4.15)= Lean Body Weight

**3)** Finally, subtract your lean bodyweight
from your total bodyweight (Total weight-Lean
Bodyweight). Once you get the result, multiply
that number by 100. Once you get the result divide it by your total
bodyweight. This final result is your percentage of body fat. à ((Total
Bodyweight - Lean Bodyweight) x 100) divided
by (Your Body Weight) = Your Percentage
of Body Fat.

**Example:**

I
weigh 190 and I have a 30.5inch waist. Therefore, step 1 is (190
x 1.082) + 94.42 = 300. Step 2 says that my lean body weight equals
300-(30.5 x 4.15)=173.425. Finally, Step 3 says that my body fat
percentage is ((190-173.425) x 100) divided by 190= 8.72%.

**For
Women:**

Before
you use the formulas, there are five measurements that are required (not fair, I know):

Measurement
1: **Bodyweight.**

Measurement
2: **Wrist Circumference** (measured at the widest point).

Measurement
3: **Waist Circumference **(measured at your umbilicus).

Measurement
4: **Hip Circumference** (measured at the widest point).

Measurement
5: **Forearm Circumference** (measured at the widest point).

**Procedure:**

**1)** Multiply your bodyweight by 0.732. à Bodyweight x .0732
= Result 1.

**2)** Add the result above to 8.987. à Result 1 + 8.987= Result
2.

**3) **Divide your wrist circumference by 3.14. à Wrist divided
by 3.14 = Result 3.

**4)** Multiply your waist measurement by 0.157. à Waist x 0.157
= Result 4.

**5)** Multiply your hip measurement by 0.249. à Hip x 0.249 =
Result 5.

**6)** Multiply your forearm measurement by 0.434. à Forearm x
0.434 = Result 6.

**7)** Add results 2 & 3. à Result 2 + Result 3 = Result 7.

**8)** Subtract Result 4 from Result 7. à Result 7 - Result 4 =
Result 8.

**9)** Subtract Result 5 from Result 8. à Result 8 - Result 5 =
Result 9.

**10)** Add Result 6 and Result 9. The result is
your lean body mass (your fat free weight) à Result 6 +
Result 9 = Lean Body Mass.

**11)** Subtract your lean body mass from your
bodyweight. Once you get the result, multiply
that number by 100. Once you get this result,
divide it by your bodyweight. à ((Bodyweight-Lean
Body Mass) x 100) divided by your bodyweight.

**Example:**

A
woman that weighs 125, and has a wrist measurement of 6.0, a waist
measurement of 24, a hip measurement of 38, and a forearm measurement
of 9.5 would calculate her body fat percentage in the following
manner. Step 1: 125 x 0.732=91.5. Step 2: 91.5 + 8.987=100.487.
Step 3: 6 divided by 3.14=1.91. Step 4: 24 x 0.157=3.768. Step
5: 38 x 0.249=9.462. Step 6: 9.5 x 0.434=4.123. Step 7: 100.487+1.91=102.397.
Step 8: 102.397-3.768=98.629. Step 9: 98.629-9.462=89.167. Step
10: 4.123+89.167=93.29 (Lean Body Weight: Fat Free Weight). Step
11: ((125-93.29) x 100) divided by 125 = (31.37 x 100) divided
by 125 = 3171 divided by 125= 25.368 (Body Fat Percentage).

Notes: The formulas above are just approximations. The goal here is to have a point of reference from which to work. I recommend that you measure your body fat every three weeks. If you see a pattern where you see yourself gaining muscle and losing fat, then you know your program is right on track. If not, examine which part of your program is not optimal. Assuming that you are following an effective training routine, look at the things that could be going wrong such as you are not getting enough rest at night or more likely you are not following your nutrition plan to the letter.

Since I like to measure my progress, and that of others, in the shortest amount of time possible, I created a computer program that once you enter the required inputs, it calculates in a microsecond your lean body mass, fat mass, and body fat percentage. It sure beats using the calculator, the pen or pencil and the piece of paper.

Have
fun!

**Hugo Rivera**

**Click
below for more:
**

**Fabulous book on habit change with fat-loss workouts by Josh Hillis & Dan John:
Fat Loss Happens on Monday**

To use our **online bodyfat calculator**

To use the **formula in an Excel
spreadsheet**

To read the **IronOnline Forum Archive**

Go back to the **8-Week On Target
Workouts**

Click
here for **sample workout routines**

May we answer any **questions for you in our forum? **

If
you haven't yet read Dave's **bodybuilding
book, Brother Iron, Sister Steel, click
here** for more information.