Heart Rate Variability

HRV Monitor

Measure the variability between your heartbeats in real time. Higher HRV = greater nervous system resilience. Use this alongside a breathwork session to see coherence in action.

Live BPM

RMSSD

Coherence

LF/HF Ratio

Input method

Tap the button each time you feel a heartbeat (fingertip on chest or wrist pulse).

Tap at least 6 times to begin measuring.

Live metrics

—

BPM

heart rate

—

RMSSD ms

beat-to-beat variability

—

SDNN ms

std dev of RR intervals

—

Coherence

rhythm regularity

LowMediumHigh

Score: 0.0 / 10

Nervous system status

Waiting for data…

Begin tapping or start the camera to see your nervous system state.

Session

0:00

elapsed

beats recorded

🌊 Practice coherence

RR interval chart (ms)

RR interval Average

Ideal coherence range: 800–1200 ms (50–75 BPM) with minimal variance

Frequency balance

LF (sympathetic) HF (parasympathetic)

LF
0.04–0.15 Hz

—

HF
0.15–0.40 Hz

—

LF/HF ratio: —

Beat history (last 20 RR intervals)

#	RR (ms)	Δ from prev	BPM	Flag
No beats recorded yet — start tapping or enable the camera.

Science

What is HRV and why does it matter?

RR Intervals

The time between consecutive heartbeats (R-peaks on an ECG) measured in milliseconds. Healthy hearts are not perfectly regular — variation is a sign of adaptability.

RMSSD

Root Mean Square of Successive Differences. The gold-standard short-term HRV metric. Higher values (>50 ms) indicate strong parasympathetic (rest & digest) tone.

Coherence

When your heart rhythm becomes smooth and sine-like — driven by breathing at ~5–6 breaths/min — it creates a state of high coherence linked to peak cognitive performance.

LF / HF Ratio

Low Frequency power (sympathetic + parasympathetic) vs High Frequency power (parasympathetic only). A ratio near 1 indicates autonomic balance. >3 suggests stress dominance.