function toggleHipField() {
var gender = document.getElementById("armyGender").value;
var hipContainer = document.getElementById("hipContainer");
var waistLabel = document.getElementById("waistLabel");
var waistHelp = document.getElementById("waistHelp");
if (gender === "female") {
hipContainer.style.display = "block";
waistLabel.innerText = "Waist Circumference (inches)";
waistHelp.innerText = "Measure at the narrowest point of the abdomen.";
} else {
hipContainer.style.display = "none";
waistLabel.innerText = "Abdominal Circumference (inches)";
waistHelp.innerText = "Measure at the navel.";
}
}
function calculateArmyBF() {
var gender = document.getElementById("armyGender").value;
var height = parseFloat(document.getElementById("armyHeight").value);
var neck = parseFloat(document.getElementById("armyNeck").value);
var waist = parseFloat(document.getElementById("armyWaist").value);
var resultDiv = document.getElementById("armyBFResult");
if (isNaN(height) || isNaN(neck) || isNaN(waist) || height <= 0 || neck <= 0 || waist <= 0) {
resultDiv.style.display = "block";
resultDiv.style.backgroundColor = "#fee2e2";
resultDiv.style.color = "#991b1b";
resultDiv.innerHTML = "Error: Please enter valid positive numbers for all measurements.";
return;
}
var bodyFat = 0;
if (gender === "male") {
// U.S. Army formula for Men (Imperial)
// %BF = 86.010 * log10(waist – neck) – 70.041 * log10(height) + 36.76
if (waist <= neck) {
resultDiv.style.display = "block";
resultDiv.style.backgroundColor = "#fee2e2";
resultDiv.style.color = "#991b1b";
resultDiv.innerHTML = "Error: Abdomen measurement must be larger than neck measurement.";
return;
}
bodyFat = 86.010 * Math.log10(waist – neck) – 70.041 * Math.log10(height) + 36.76;
} else {
// U.S. Army formula for Women (Imperial)
// %BF = 163.205 * log10(waist + hip – neck) – 97.43 * log10(height) – 78.387
var hip = parseFloat(document.getElementById("armyHip").value);
if (isNaN(hip) || hip <= 0) {
resultDiv.style.display = "block";
resultDiv.style.backgroundColor = "#fee2e2";
resultDiv.style.color = "#991b1b";
resultDiv.innerHTML = "Error: Please enter a valid hip measurement.";
return;
}
if ((waist + hip) <= neck) {
resultDiv.style.display = "block";
resultDiv.style.backgroundColor = "#fee2e2";
resultDiv.style.color = "#991b1b";
resultDiv.innerHTML = "Error: Sum of waist and hip must be larger than neck measurement.";
return;
}
bodyFat = 163.205 * Math.log10(waist + hip – neck) – 97.43 * Math.log10(height) – 78.387;
}
bodyFat = Math.round(bodyFat * 10) / 10;
resultDiv.style.display = "block";
resultDiv.style.backgroundColor = "#ecfdf5";
resultDiv.style.color = "#065f46";
resultDiv.innerHTML = "
Your Estimated Body Fat:
" + bodyFat + "%Based on AR 600-9 circumference methods.";
}
Understanding the Army Body Fat Standards (AR 600-9)
The United States Army uses a specific circumference-based method, often referred to as the "Tape Test," to determine if a Soldier meets the body composition standards outlined in Army Regulation 600-9. While Body Mass Index (BMI) is used as an initial screening tool, the body fat calculator is the official tool for determining compliance when a Soldier exceeds their weight-for-height allowance.
How the Army Tape Test Works
The Army body fat calculator uses equations developed by the U.S. Army Research Institute of Environmental Medicine. These formulas differ by gender and rely on specific anatomical measurements:
For Men: Measurements are taken at the neck and the abdomen (at the level of the navel).
For Women: Measurements are taken at the neck, the narrowest part of the waist, and the widest part of the hips.
Maximum Allowable Body Fat Percentages
Compliance depends on age. As Soldiers age, the maximum allowable body fat percentage increases slightly. Below are the standard limits for both Male and Female Soldiers:
Age Group
Male Limit
Female Limit
17 – 20
20%
30%
21 – 27
22%
32%
28 – 39
24%
34%
40+
26%
36%
How to Measure Correctly
Precision is critical for an accurate Army Tape Test. Even a quarter-inch difference can significantly impact the final percentage.
Height: Measure without shoes, standing tall against a flat surface.
Neck: Measure just below the larynx (Adam's apple) with the tape slanted slightly downward toward the front.
Abdomen (Men): Measure horizontally at the level of the navel (belly button). Do not suck in the gut.
Waist (Women): Measure at the narrowest point of the torso (usually above the belly button).
Hips (Women): Measure at the widest part of the buttocks, ensuring the tape remains horizontal.
What Happens if You Fail?
Soldiers who exceed their body fat allowance are entered into the Army Body Composition Program (ABCP). This program includes mandatory nutritional counseling, exercise guidance, and monthly progress checks. Failure to make "satisfactory progress" in the ABCP can lead to administrative actions, including the inability to attend professional schools, bars to reenlistment, or separation from service.
Disclaimer: This calculator provides an estimate based on the AR 600-9 formulas. For official results, measurements must be performed by certified Army personnel using calibrated equipment.