Use this calculator to estimate your body fat percentage according to the U.S. Army's tape test methodology. This method uses specific circumference measurements and height to determine body fat, which is a key component of the Army's physical readiness standards.
Male
Female
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var femaleFields = document.getElementById('femaleFields');
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function calculateBodyFat() {
var genderMale = document.getElementById('genderMale').checked;
var heightInches = parseFloat(document.getElementById('heightInches').value);
var neckCircumference = parseFloat(document.getElementById('neckCircumference').value);
var bodyFatPercentage;
var resultDiv = document.getElementById('result');
// Input validation
if (isNaN(heightInches) || heightInches <= 0 ||
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resultDiv.innerHTML = "Please enter valid positive numbers for height and neck circumference.";
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if (genderMale) {
var abdomenCircumference = parseFloat(document.getElementById('abdomenCircumference').value);
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resultDiv.innerHTML = "Please enter a valid positive number for abdomen circumference.";
return;
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if (abdomenCircumference <= neckCircumference) {
resultDiv.innerHTML = "Abdomen circumference must be greater than neck circumference for a valid calculation.";
return;
}
// Male formula: 86.010 * log10(abdomen – neck) – 70.041 * log10(height) + 36.76
var log10AbdomenNeck = Math.log(abdomenCircumference – neckCircumference) / Math.log(10);
var log10Height = Math.log(heightInches) / Math.log(10);
bodyFatPercentage = (86.010 * log10AbdomenNeck) – (70.041 * log10Height) + 36.76;
} else { // Female
var waistCircumference = parseFloat(document.getElementById('waistCircumference').value);
var hipCircumference = parseFloat(document.getElementById('hipCircumference').value);
if (isNaN(waistCircumference) || waistCircumference <= 0 ||
isNaN(hipCircumference) || hipCircumference <= 0) {
resultDiv.innerHTML = "Please enter valid positive numbers for waist and hip circumference.";
return;
}
if ((waistCircumference + hipCircumference) <= neckCircumference) {
resultDiv.innerHTML = "The sum of waist and hip circumference must be greater than neck circumference for a valid calculation.";
return;
}
// Female formula: 163.205 * log10(waist + hip – neck) – 97.684 * log10(height) – 78.387
var log10WaistHipNeck = Math.log(waistCircumference + hipCircumference – neckCircumference) / Math.log(10);
var log10Height = Math.log(heightInches) / Math.log(10);
bodyFatPercentage = (163.205 * log10WaistHipNeck) – (97.684 * log10Height) – 78.387;
}
if (isNaN(bodyFatPercentage)) {
resultDiv.innerHTML = "An error occurred during calculation. Please check your inputs.";
} else {
resultDiv.innerHTML = "Your estimated Army Body Fat Percentage is: " + bodyFatPercentage.toFixed(1) + "%";
}
}
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Understanding the U.S. Army Body Fat Calculation
The U.S. Army utilizes body fat percentage as a critical component of its physical readiness standards, alongside the Army Combat Fitness Test (ACFT). While the ACFT assesses physical performance, body fat standards ensure soldiers maintain a healthy body composition, which is vital for overall health, injury prevention, and sustained operational effectiveness. The Army's method for estimating body fat is commonly known as the "tape test."
Why Body Fat Matters in the Army
Physical Readiness: Excessive body fat can hinder a soldier's ability to perform physically demanding tasks, such as carrying heavy loads, maneuvering quickly, or enduring long periods of physical exertion.
Health and Wellness: Maintaining a healthy body fat percentage reduces the risk of chronic diseases and injuries, contributing to a soldier's long-term health and career longevity.
Professional Appearance: Body composition standards also contribute to a professional military appearance, reflecting discipline and readiness.
The Army Tape Test Methodology
The Army's body fat calculation method relies on a series of circumference measurements taken with a tape measure. These measurements, combined with height and gender, are plugged into specific regression equations to estimate body fat percentage. It's important to note that this is an estimation method and may not be as precise as laboratory methods like DEXA scans, but it provides a practical and consistent field assessment.
Measurements for Males:
Height: Measured in inches.
Neck Circumference: Measured horizontally at the point just below the larynx (Adam's apple), with the tape sloping slightly upward at the back.
Abdomen Circumference: Measured horizontally at the navel (belly button). The soldier should relax and breathe normally; the measurement is taken at the end of a normal exhalation.
Measurements for Females:
Height: Measured in inches.
Neck Circumference: Measured horizontally at the point just below the larynx, with the tape sloping slightly upward at the back.
Waist Circumference: Measured horizontally at the narrowest point of the natural waist, usually above the navel and below the rib cage. If no natural waist is apparent, it's measured at the navel. The soldier should relax and breathe normally; the measurement is taken at the end of a normal exhalation.
Hip Circumference: Measured horizontally around the largest protrusion of the gluteal muscles (buttocks), with the feet together.
How the Calculator Works
Our Army Body Fat Calculator uses the official regression equations derived from Department of Defense Instruction 1308.3. You simply input your gender, height, and the required circumference measurements in inches. The calculator then applies the appropriate formula: