Calculate PSA Density and compare results against age-specific reference ranges.
PSA Density (PSAD)
Age-Specific Status
Understanding PSA Levels and PSA Density
Prostate-Specific Antigen (PSA) is a protein produced by both normal and neoplastic cells of the prostate gland. While a high PSA level can be a sign of prostate cancer, it can also be caused by non-cancerous conditions like Benign Prostatic Hyperplasia (BPH) or prostatitis.
This calculator evaluates two critical clinical metrics: PSA Density and Age-Specific Reference Ranges. These metrics help clinicians differentiate between age-related prostate enlargement and potential malignancy.
What is PSA Density (PSAD)?
PSA Density is calculated by dividing the total PSA level by the volume of the prostate gland (usually measured via ultrasound or MRI). Because larger prostates naturally produce more PSA, a high total PSA in a very large prostate may be less concerning than the same PSA level in a small prostate.
Formula: PSA Density = Total PSA (ng/mL) ÷ Prostate Volume (cc)
Clinical Threshold: A PSA Density higher than 0.15 ng/mL/cc is often considered a threshold where further investigation (like a biopsy) may be warranted.
Age-Specific PSA Reference Ranges
PSA levels naturally increase as men age. Using a single cutoff (like 4.0 ng/mL) for all men can lead to over-diagnosis in older men and under-diagnosis in younger men. Standard clinical references are:
Age Range
Normal PSA Range (ng/mL)
40–49 years
0 – 2.5
50–59 years
0 – 3.5
60–69 years
0 – 4.5
70–79 years
0 – 6.5
Example Calculation
If a 65-year-old man has a PSA of 5.2 ng/mL and a prostate volume of 50 cc:
Age Check: His PSA (5.2) is slightly above the 60-69 range (4.5).
PSA Density: 5.2 / 50 = 0.104 ng/mL/cc.
Conclusion: While his total PSA is high for his age, his PSA Density is below the 0.15 threshold, suggesting the elevation might be due to the size of the prostate (BPH) rather than cancer.
Important Medical Disclaimer: This tool is for educational purposes only and does not constitute medical advice. PSA levels can be affected by recent activity, infections, and medications. Always consult with a urologist or healthcare provider to interpret your results.
function calculatePSA() {
var psa = parseFloat(document.getElementById('psaLevel').value);
var age = parseInt(document.getElementById('patientAge').value);
var volume = parseFloat(document.getElementById('prostateVolume').value);
var resultDiv = document.getElementById('psaResults');
var psadDisplay = document.getElementById('psadValue');
var ageRefDisplay = document.getElementById('ageRefStatus');
var interpDisplay = document.getElementById('psaInterpretation');
if (isNaN(psa) || isNaN(age) || isNaN(volume) || volume <= 0) {
alert("Please enter valid positive numbers for all fields.");
return;
}
// Calculate PSA Density
var psad = psa / volume;
psadDisplay.innerHTML = psad.toFixed(3) + " ng/mL/cc";
// Age Specific Logic
var ageLimit = 0;
if (age < 40) ageLimit = 2.0;
else if (age < 50) ageLimit = 2.5;
else if (age < 60) ageLimit = 3.5;
else if (age < 70) ageLimit = 4.5;
else ageLimit = 6.5;
var ageStatusText = "";
if (psa <= ageLimit) {
ageStatusText = "Within Normal Range";
ageRefDisplay.style.color = "#27ae60";
} else {
ageStatusText = "Above Normal Range";
ageRefDisplay.style.color = "#e74c3c";
}
ageRefDisplay.innerHTML = ageStatusText + " (Limit: " + ageLimit + ")";
// General Interpretation
var interp = "Analysis: ";
if (psad > 0.15) {
interp += "The PSA Density is high (> 0.15), which may indicate a higher risk of malignancy regardless of age-specific ranges. ";
} else {
interp += "The PSA Density is within a lower risk profile ( ageLimit) {
interp += "However, because the total PSA is above the age-specific reference of " + ageLimit + " ng/mL, clinical correlation is advised.";
} else {
interp += "The total PSA level is also consistent with typical levels for this age group.";
}
interpDisplay.innerHTML = interp;
resultDiv.style.display = "block";
}