Estimate your RR and calculate deviation percentages similar to WHOOP algorithms.
Count the number of full inhalations/exhalations (RSA cycles) during your measurement window.
How long did you measure? (e.g., 60 seconds, 120 seconds).
Enter your typical nightly average to calculate deviation (usually 12-20 rpm).
Calculated Respiratory Rate:– rpm
Calculation Logic:60 / Cycle Time
Deviation from Baseline:0%
How Does WHOOP Calculate Respiratory Rate?
Unlike standard medical devices that might use chest straps or airflow sensors to count breaths directly, WHOOP calculates respiratory rate (RR) using a sophisticated phenomenon known as Respiratory Sinus Arrhythmia (RSA). This method allows the device to determine your breathing rate strictly from your heart rate data, measured via the optical sensor on your wrist.
The Principle: Respiratory Sinus Arrhythmia (RSA)
To understand how WHOOP calculates respiratory rate, you must understand the biological link between your heart and your lungs:
Inhalation: When you breathe in, your heart rate naturally increases slightly.
Exhalation: When you breathe out, your heart rate naturally decreases slightly.
This cyclical fluctuation is RSA. The WHOOP strap uses Photoplethysmography (PPG)—the green LEDs on the back of the strap—to monitor your heart beat-by-beat with high precision. By analyzing the timing between heartbeats, the algorithm detects these subtle waves of acceleration and deceleration.
The Calculation Process
The calculation performed by the WHOOP algorithm generally follows these steps:
Data Collection: The sensor collects raw PPG data throughout the night, specifically focusing on periods of Deep Sleep (Slow Wave Sleep), where heart rate is most consistent and motion artifacts are minimal.
RSA Extraction: The algorithm filters the heart rate signal to isolate the frequency of the RSA cycles. It looks for the "peaks" (end of inhalation) and "troughs" (end of exhalation) in the heart rate variability stream.
Frequency Analysis: Once the cycles are identified, the device calculates the frequency. If one full RSA cycle (inhale + exhale) takes 4 seconds, the calculation is 60 seconds / 4 seconds = 15 breaths per minute (rpm).
Averaging: WHOOP aggregates these measurements over the duration of your sleep to provide a single, highly accurate nightly average.
Why Respiratory Rate Stability Matters
One of the most valuable aspects of the WHOOP respiratory rate metric is its stability. Unlike Heart Rate Variability (HRV) or Resting Heart Rate (RHR), which can fluctuate daily based on exercise or hydration, a healthy person's respiratory rate is remarkably consistent.
Because of this stability, the Deviation Calculation (featured in the calculator above) is critical. A sudden increase in respiratory rate is often a leading indicator of physiological strain or illness.
Interpreting the Numbers
12 to 20 rpm: This is considered the normal range for most healthy adults.
< 10% Deviation: Fluctuations within this range are typically normal and considered "stable."
> 20% Increase: A significant spike (e.g., jumping from 14 rpm to 17 rpm) can be an early warning sign of a respiratory tract infection or significant systemic fatigue.
Why WHOOP Measures RR During Sleep
Measuring respiratory rate during the day is difficult because it is easily influenced by conscious thought, movement, and stress. If you think about your breathing, you alter it. By measuring RR during sleep, and specifically utilizing the autonomic nervous system's control over RSA, WHOOP captures a "true" baseline uncorrupted by external factors.
function calculateWhoopRR() {
// Get input values
var breathCount = document.getElementById('breathCount').value;
var durationSeconds = document.getElementById('durationSeconds').value;
var baselineRR = document.getElementById('baselineRR').value;
// Sanitize and Parse
var breaths = parseFloat(breathCount);
var seconds = parseFloat(durationSeconds);
var baseline = parseFloat(baselineRR);
// Validation
if (isNaN(breaths) || isNaN(seconds) || seconds 0) {
var diff = calculatedRR – baseline;
var percentChange = (diff / baseline) * 100;
var sign = percentChange > 0 ? "+" : "";
document.getElementById('displayDeviation').innerHTML = sign + percentChange.toFixed(1) + "%";
deviationRow.style.display = 'flex';
// Status Logic based on WHOOP/Medical general guidelines
// Note: This is an estimation logic
statusBox.style.display = 'block';
statusBox.className = 'rr-status-box'; // reset class
if (percentChange > 20) {
statusBox.innerHTML = "WARNING: Significant Elevation (>20%). Monitor for symptoms.";
statusBox.classList.add('status-warning');
} else if (percentChange > 10) {
statusBox.innerHTML = "CAUTION: Mild Elevation (10-20%). Watch recovery.";
statusBox.classList.add('status-elevated');
} else if (percentChange < -10) {
statusBox.innerHTML = "NOTE: Lower than average. Check sensor fit or recovery.";
statusBox.classList.add('status-elevated');
} else {
statusBox.innerHTML = "STATUS: Stable (Within normal variation).";
statusBox.classList.add('status-normal');
}
} else {
deviationRow.style.display = 'none';
statusBox.style.display = 'none';
}
}