Cost of Gas Calculator

Body Fat Percentage Calculator – US Navy Method .bf-calc-container { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; max-width: 800px; margin: 20px auto; padding: 25px; border: 1px solid #e1e1e1; border-radius: 12px; background-color: #ffffff; color: #333; box-shadow: 0 4px 15px rgba(0,0,0,0.05); } .bf-calc-header { text-align: center; margin-bottom: 25px; } .bf-calc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; } .bf-input-group { margin-bottom: 15px; } .bf-input-group label { display: block; font-weight: 600; margin-bottom: 8px; font-size: 14px; } .bf-input-group input, .bf-input-group select { width: 100%; padding: 12px; border: 1px solid #ccc; border-radius: 6px; font-size: 16px; box-sizing: border-box; } .bf-btn-calculate { grid-column: span 2; background-color: #2c3e50; color: white; padding: 15px; border: none; border-radius: 6px; font-size: 18px; font-weight: bold; cursor: pointer; transition: background-color 0.3s; margin-top: 10px; } .bf-btn-calculate:hover { background-color: #1a252f; } .bf-result-box { margin-top: 25px; padding: 20px; background-color: #f8f9fa; border-radius: 8px; text-align: center; display: none; } .bf-result-value { font-size: 32px; font-weight: 800; color: #27ae60; margin: 10px 0; } .bf-category { font-size: 18px; font-weight: 600; color: #555; } .bf-article { margin-top: 40px; line-height: 1.6; color: #444; } .bf-article h2 { color: #2c3e50; border-bottom: 2px solid #eee; padding-bottom: 10px; } .bf-article table { width: 100%; border-collapse: collapse; margin: 20px 0; } .bf-article th, .bf-article td { border: 1px solid #ddd; padding: 12px; text-align: left; } .bf-article th { background-color: #f2f2f2; } @media (max-width: 600px) { .bf-calc-grid { grid-template-columns: 1fr; } .bf-btn-calculate { grid-column: span 1; } }

Body Fat Percentage Calculator

Estimate your body composition using the US Navy Fitness Method.

Male Female
Your Estimated Body Fat
0%

Understanding Body Fat Percentage

Body fat percentage is the total mass of fat divided by total body mass, multiplied by 100. Unlike Body Mass Index (BMI), which only uses height and weight, body fat percentage accounts for the distinction between muscle mass and fat mass, making it a more accurate health indicator for athletes and active individuals.

The US Navy Method Explained

The US Navy Method is a widely used formula developed by the Naval Health Research Center. It provides an estimate of body fat by measuring the circumferences of various body parts. While DEXA scans are the gold standard, this method is surprisingly accurate (within 3-4% margin of error) and requires only a measuring tape.

Measurement Tips for Accuracy:

  • Neck: Measure below the larynx (Adam's apple), sloping slightly downward to the front.
  • Waist (Men): Measure horizontally at the navel level.
  • Waist (Women): Measure at the narrowest point of the abdomen (usually above the navel).
  • Hips (Women only): Measure at the widest point of the buttocks.
  • Height: Measure without shoes, standing straight against a wall.

Body Fat Percentage Categories (ACE Chart)

Description Women (%) Men (%)
Essential Fat 10-13% 2-5%
Athletes 14-20% 6-13%
Fitness 21-24% 14-17%
Average 25-31% 18-24%
Obese 32%+ 25%+

Calculation Example

For a male with a height of 180cm, a waist of 90cm, and a neck of 40cm:

The formula uses logarithmic calculations: 495 / (1.0324 - 0.19077 * log10(waist - neck) + 0.15456 * log10(height)) - 450. In this scenario, the estimated body fat would be approximately 18.5%, placing him in the "Average" fitness category.

function toggleHipInput() { var gender = document.getElementById("bfGender").value; var hipContainer = document.getElementById("hipContainer"); if (gender === "female") { hipContainer.style.display = "block"; } else { hipContainer.style.display = "none"; } } function calculateBodyFat() { var gender = document.getElementById("bfGender").value; var height = parseFloat(document.getElementById("bfHeight").value); var neck = parseFloat(document.getElementById("bfNeck").value); var waist = parseFloat(document.getElementById("bfWaist").value); var hip = parseFloat(document.getElementById("bfHip").value); var resultDiv = document.getElementById("bfResult"); var valueDisplay = document.getElementById("bfValue"); var statusDisplay = document.getElementById("bfStatus"); var descDisplay = document.getElementById("bfDescription"); if (!height || !neck || !waist || (gender === "female" && !hip)) { alert("Please enter all required measurements."); return; } var bodyFat = 0; if (gender === "male") { // US Navy Male Formula // BF = 495 / (1.0324 – 0.19077 * log10(waist – neck) + 0.15456 * log10(height)) – 450 bodyFat = 495 / (1.0324 – 0.19077 * Math.log10(waist – neck) + 0.15456 * Math.log10(height)) – 450; } else { // US Navy Female Formula // BF = 495 / (1.29579 – 0.35004 * log10(waist + hip – neck) + 0.22100 * log10(height)) – 450 bodyFat = 495 / (1.29579 – 0.35004 * Math.log10(waist + hip – neck) + 0.22100 * Math.log10(height)) – 450; } if (isNaN(bodyFat) || bodyFat < 0) { alert("Calculation error. Please check your measurements. Ensure waist is larger than neck."); return; } var category = ""; if (gender === "male") { if (bodyFat < 6) category = "Essential Fat"; else if (bodyFat < 14) category = "Athlete"; else if (bodyFat < 18) category = "Fitness"; else if (bodyFat < 25) category = "Average"; else category = "Obese"; } else { if (bodyFat < 14) category = "Essential Fat"; else if (bodyFat < 21) category = "Athlete"; else if (bodyFat < 25) category = "Fitness"; else if (bodyFat < 32) category = "Average"; else category = "Obese"; } valueDisplay.innerHTML = bodyFat.toFixed(1) + "%"; statusDisplay.innerHTML = "Category: " + category; descDisplay.innerHTML = "Based on your measurements, you fall into the " + category + " category. Track this number over time to monitor your fitness progress."; resultDiv.style.display = "block"; resultDiv.scrollIntoView({ behavior: 'smooth' }); }

Leave a Comment