Heart Rate Variability (HRV) Resonance Finder

HRV Resonance Finder

{{ cycle_seconds.toFixed(2) }} s / cycle · {{ summaryPattern }}

Age {{ age }}y {{ height_cm }} cm {{ sexLabel }} RHR {{ rhr_bpm }} bpm Warnings: {{ warnings.length }}

Age: years

Height: cm

Sex:

Resting heart rate: bpm

Exhale bias (%):

{{ exhale_bias_percent }}%

Hold after inhale (s):

Hold after exhale (s):

Vagal tone (z):

Fitness (z):

Curve width + (bpm):

Round phase durations:

Metric	Value	Copy
Resonant rate (bpm)	{{ resonance_bpm.toFixed(2) }}
Cycle length (s)	{{ cycle_seconds.toFixed(2) }}
Inhale (s)	{{ inhale_s.toFixed(2) }}
Hold after inhale (s)	{{ eff_hold_in_s.toFixed(2) }}
Exhale (s)	{{ exhale_s.toFixed(2) }}
Hold after exhale (s)	{{ eff_hold_out_s.toFixed(2) }}
Recommended window (bpm)	{{ window_low.toFixed(2) }} – {{ window_high.toFixed(2) }}
Status	{{ statusLine }}

This tool estimates a resonance-breathing pace from simple inputs; it is not a medical device. Breathe comfortably. Stop if you feel dizzy or unwell.

Tags: Breathwork , Mindfulness

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Resonance breathing is the tempo of breath cycles that tends to maximize vagal calm and smooth heart rhythm. Many people use it to settle attention and reduce stress during short practice sessions. A resonant breathing rate calculator helps you pick a steady pace that fits your body and feels natural.

You provide a few simple cues about yourself and your resting pulse, and the estimator suggests a breaths per minute target with a matching cycle length. It also breaks the cycle into inhale, optional holds, and exhale so the pattern is easy to follow.

A typical session begins by settling into a relaxed seat, then matching your breath to the suggested rhythm for a few minutes. If the pace feels too quick or too slow, adjust within the recommended window and prioritize comfort.

As one example, a healthy adult might land near six breaths per minute and discover that about five seconds in and five seconds out feels calm and sustainable. Small changes in holds or a slightly longer exhale can be explored without strain.

Breathe gently and stop if you feel lightheaded or unwell. This tool provides informational estimates and does not substitute professional advice.

Technical Details:

The measure of interest is the breathing rate that elicits a strong vagal response, summarized as a breaths per minute target and a cycle time in seconds. A simple heuristic combines age, height, sex selection, resting heart rate, and two optional z‑style sliders that proxy general vagal tone and cardio fitness. The result anchors a bell‑shaped response curve to show a comfortable window rather than a single rigid number.

Computation proceeds by adjusting a neutral starting rate with small offsets, clamping to a sensible band, and rounding for display. The cycle is then partitioned into inhale and exhale fractions, with optional holds and an exhale bias that lengthens one phase relative to the other without exceeding the cycle span.

Results are interpreted as a center and a recommended window bounded by low and high rates. Values near the edges are still usable when they feel easy and smooth; comfort, safety, and regular practice take priority over chasing a specific digit.

Comparisons across people or across days are meaningful only when inputs are measured similarly and the pattern remains comfortable. Height is treated as a proxy for lung volume, and resting pulse is a practical stand‑in for baseline autonomic load.

\begin{array}{lll} r & = & clamp (4, 8, {round}_{2} (5.5 + d_{age} + d_{h} + d_{sex} + d_{rhr} + d_{vag} + d_{fit})) \\ T & = & \frac{60}{r} \\ b & = & \frac{bias}{100} \\ f_{ex} & = & clamp (0, 1, 0.5 + \frac{b}{2}) \\ f_{in} & = & 1 - f_{ex} \\ avail & = & \max (0, T - h_{i} - h_{o}) \\ t_{in} & = & avail \cdot f_{in} \\ t_{ex} & = & avail \cdot f_{ex} \\ w & = & clamp (0.15, 0.8, 0.35 \cdot clamp (0.7, 1.4, 1 - 0.08 \cdot z_{vag} - 0.04 \cdot z_{fit}) + add) \\ s & = & \frac{w}{\sqrt{2 \cdot \ln (2)}} \\ r_{low} & = & clamp (3, 9, r - w) \\ r_{high} & = & clamp (3, 9, r + w) \end{array}

Symbols and units
Symbol	Meaning	Unit/Datatype	Source
r	Resonance rate	breaths per minute	Derived
T	Cycle length	seconds	Derived
b	Exhale bias fraction	0–1	Input
f_ex, f_in	Phase fractions	0–1	Derived
h_i, h_o	Holds after inhale/exhale	seconds	Input
w	Response half‑width	breaths per minute	Derived
s	Gaussian sigma	breaths per minute	Derived
r_low, r_high	Recommended window	breaths per minute	Derived

Worked example. Inputs: age 35, height 170 cm, sex “other”, resting heart rate 60 bpm, holds 0 s, bias 0%.

\begin{matrix} r & = & 5.64 bpm \\ T & = & 10.64 s \\ t_{in} & = & 5.32 s \\ t_{ex} & = & 5.32 s \\ r_{low} & = & 5.29 \\ r_{high} & = & 5.99 \end{matrix}

Interpretation: aim near 5.6 bpm; explore 5.3 to 6.0 bpm if comfort improves.

Interpretation thresholds
Threshold Band	Lower Bound	Upper Bound	Interpretation	Action Cue
Common resonance band	4.5	7.5	Most estimates fall here.	Stay comfortable; adjust within the window.
Outside common band	< 4.5	> 7.5	Estimator flags as atypical.	Recheck inputs; prioritize ease and safety.

Units, precision & rounding:

Displayed values use two decimals; times are in seconds, rates in breaths per minute.
Optional rounding snaps phase durations to the nearest 0.1 s.
All calculations clamp values to defined bounds for stability.

Validation & bounds:

Input validation rules
Field	Type	Min	Max	Step/Pattern	Error Text	Placeholder
Age	number	1	120	1	Age must be between 1 and 120.	—
Height (cm)	number	80	250	1	Height must be between 80 and 250 cm.	—
Sex	select	—	—	male/female/other	—	—
Resting heart rate	number	25	180	1	Resting heart rate must be between 25 and 180 bpm.	—
Exhale bias (%)	number	−40	40	1	—	—
Hold after inhale (s)	number	0	—	0.1	Hold durations cannot be negative.	—
Hold after exhale (s)	number	0	—	0.1	Hold durations cannot be negative.	—
Combined holds	constraint	—	T − 0.01	—	Holds exceed or leave no time for inhale/exhale at this rate.	—
Vagal tone (z)	number	−3	3	0.5	—	—
Fitness (z)	number	−3	3	0.5	—	—
Curve width + (bpm)	number	0	1	0.05	—	—
Round phase durations	boolean	—	—	on/off	—	—

I/O & formats:

Inputs and outputs
Input	Accepted Families	Output	Encoding/Precision	Rounding
Age, height, sex, resting heart rate, holds, exhale bias, z‑values	Numeric fields and a single selection	Breaths per minute, cycle time, phase timings, recommended window	On‑screen table; CSV and JSON available	Two decimals; optional 0.1 s for phases

Privacy & compliance:

All processing happens in the browser; no data is transmitted or stored server‑side. CSV and JSON exports are generated locally.

This tool provides informational estimates and does not substitute professional advice.

Assumptions & limitations:

Heuristic estimate, not a measurement of actual cardiorespiratory resonance.
Height is a coarse proxy for lung volume; individuals vary. Heads‑up
Resting heart rate should be taken in a calm, seated state.
Sex selection applies a very small offset only.
Holds reduce available inhale/exhale time and can make a pace feel harder.
Exhale bias changes phase balance without changing cycle length.
Window width depends on optional z‑inputs and an adjustable width add‑on.
Gaussian curve is illustrative; it does not reflect clinical diagnostics. Heads‑up

Edge cases & error sources:

Age outside 1–120 triggers an error.
Height outside 80–250 cm triggers an error.
Resting heart rate outside 25–180 bpm triggers an error.
Negative hold durations are invalid.
Combined holds that nearly equal the cycle leave no time for breathing.
Extreme exhale bias can feel uncomfortable despite valid math.
Very low or high estimates outside 4.5–7.5 bpm are flagged as atypical.
Rounding to 0.1 s can push borderline sums over limits.
Unreliable resting heart rate readings skew the estimate.
Entering height in inches instead of centimeters yields unrealistic results.

Step‑by‑Step Guide:

Resonance breathing is summarized as a rate target with a comfortable window.

Enter Age, Height, and Sex.
Add your Resting heart rate in bpm.
Open Advanced to set optional holds or an exhale bias.
Review the suggested rate, cycle time, and phase timings.
Use the curve and window to explore nearby comfortable paces.
Copy or download the metrics if you wish to compare sessions.

Example. Age 35, height 170 cm, resting pulse 60 bpm, no holds: target ≈ 5.6 bpm; inhale ≈ 5.3 s; exhale ≈ 5.3 s.

Finish by practicing the pattern that feels calm and easy to sustain.

FAQ:

Is my data stored?

No. Calculations run in your browser and exports are created locally.

No server‑side storage.

How accurate is the estimate?

It is a practical starting point that reflects simple correlates of breathing comfort. Adjust within the window to match ease and smoothness.

Estimator, not a clinical test.

What units are used?

Rates are in breaths per minute, times are in seconds, and bias is a percent with zero meaning balanced phases.

Two‑decimal display.

Can I use it offline?

Core calculations work without a connection; the chart may require a charting component to be available.

Functionality can vary by device.

Does it require an account or payment?

No account is needed and there is no payment flow in the package.

Use as provided.

What does a “borderline” result mean?

Values near the window edges are still fine when they feel easy. Stay within the window and favor comfort over exactness.

Listen to your body.

How can I change the breathing style?

Use the exhale bias to lengthen one phase and add short holds if they feel pleasant. Keep total holds below the cycle length.

Comfort first.

Why might the chart and window widen?

The response width adapts to optional z‑inputs and any width addition you choose, affecting both the curve and the recommended window.

Exploratory visualization.

Troubleshooting:

“Age must be between 1 and 120.” — correct the number.
“Height must be between 80 and 250 cm.” — use centimeters.
“Resting heart rate must be between 25 and 180 bpm.” — recheck your reading.
“Holds exceed or leave no time…” — shorten holds or adjust the rate.
Numbers look odd — verify units and remove extra spaces.
Chart missing — the charting component may be unavailable; results still compute.

If you feel dizzy, short of breath, or unwell, stop immediately and return to normal breathing.

Advanced Tips:

Tip Take resting heart rate after three minutes of quiet sitting.
Tip Compare sessions at the same time of day for consistency.
Tip Start with zero holds, then add short pauses if they feel pleasant.
Tip Use a gentle exhale bias only if it makes breathing easier.
Tip Keep shoulders relaxed and breathe through the nose when possible.
Tip Revisit the window after a week to see if comfort shifts slightly.

Glossary:

Resonance rate: Breathing tempo linked to a strong vagal response.
Cycle length: Time for one full breath in seconds.
Exhale bias: Fraction that lengthens exhale relative to inhale.
Hold: Pause after inhale or exhale measured in seconds.
Window: Low to high range around the center rate.
Sigma: Width parameter of a Gaussian curve.