Breathing Pacer

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Breathing cycles are deliberate patterns of inhale, optional holds, and exhale that set a steady rhythm for calm and focus. You set the durations that feel comfortable, then watch the pace readout to understand how the cycle translates into breaths per minute.

Results show a simple rate and a clear sequence so you can practice with attention rather than guesswork. Presets mirror familiar patterns like equal in and out or box timing, while custom values let you fine tune longer exhales for relaxation or add gentle pauses between phases.

A short countdown can help you settle before the first inhale, and optional audio or vibration cues make it easier to follow the transitions without looking. If you feel lightheaded, shorten the holds or stop and return when comfortable.

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

Technical Details:

The underlying quantities are the durations of four phases measured in seconds: inhale, hold after inhale, exhale, and hold after exhale. From these the pace is summarized as breaths per minute (BPM), reflecting the number of full cycles completed in one minute.

The computation first adds the four phase durations to obtain the cycle length, then converts that time into a rate. This transformation is meaningful because it normalizes any combination of in, hold, out, and hold into a single comparable measure of pacing.

\begin{array}{l} S & = & t_{in} + t_{h1} + t_{out} + t_{h2} \\ B & = & \frac{60}{S} \end{array}

Symbols and units used in formulas
Symbol	Meaning	Unit/Datatype	Source
t_in	Inhale duration	s (number)	Input
t_h1	Hold after inhale	s (number)	Input
t_out	Exhale duration	s (number)	Input
t_h2	Hold after exhale	s (number)	Input
S	Cycle length	s (number)	Derived
B	Breaths per minute	bpm (number)	Derived

Worked example: Inhale 5 s, hold 0 s, exhale 5 s, hold 0 s → S = 10 s; then B = 60 / 10 = 6.00 bpm.

Comparability improves when you keep body position and breathing route consistent across sessions. Results are most interpretable within the same person across time rather than between people with different lung volumes or habits.

Variables & parameters

Controllable parameters and typical ranges
Parameter	Meaning	Typical Range	Notes
Preset	Predefined timing pattern	Box, 4‑7‑8, 7‑11, etc.	Custom allows any durations.
Session length	Target run time	0–120 min	0 means open‑ended.
Countdown	Delay before start	0–10 s	Default 3 s.
Audio volume	Phase change beep	0–100 %	0 disables sound.
Beep frequency	Tone pitch	440–1200 Hz	Minimum accepted 100 Hz.
Beep duration	Tone length	80–200 ms	UI minimum 40 ms.
Vibrate	Haptic at transitions	On/Off	Device support required.
Prevent sleep	Screen wake lock	On/Off	Requested while running.
Easing	Visual pacing curve	Sine, Linear, Ease‑in‑out	Visual only.

Units, precision & rounding

BPM displays with two decimals; durations in the table display with two decimals; JSON stores elapsed and duration with three decimals.
Decimal separator is a dot; time readouts use the current locale for strings.

Validation & bounds extracted from the app

Inputs and constraints
Field	Type	Min	Max	Step/Pattern	Error Text
Inhale	number	0	—	0.1 s	—
Hold after inhale	number	0	—	0.1 s	—
Exhale	number	0	—	0.1 s	—
Hold after exhale	number	0	—	0.1 s	—
Session length	number	0	—	1 min	0 for open‑ended.
Countdown	number	0	—	1 s	—
Audio volume	range	0	100	1 %	0 disables audio.
Beep frequency	number	100	—	1 Hz	—
Beep duration	number	40	—	10 ms	—
Vibrate	boolean	—	—	—	Device support required.
Prevent sleep	boolean	—	—	—	Requests wake lock.
Easing	enum	—	—	sine\|linear\|easeInOut	—

I/O formats

Inputs and outputs summary
Input	Accepted Families	Output	Encoding/Precision	Rounding
Phase durations	Numeric seconds	BPM readout	Number	Two decimals
Session controls	Numeric and toggles	Timeline table	Local time strings; numbers	Two decimals (display)
—	—	Session JSON	UTF‑8 text; three‑decimal numbers	As stored
—	—	Timeline CSV	Comma‑separated text	As stored

Privacy & compliance

All calculations and timeline generation occur on your device. Copy and download actions create local files or clipboard entries. A charting script may be fetched to render visuals. No data is transmitted or stored server‑side.

Assumptions & limitations

Session ends automatically when the configured minutes elapse; zero minutes runs until stopped.
Visual easing affects animations only, not timing math.
Audio and vibration depend on device capabilities and user permissions.
Wake lock is requested only when enabled and may be denied by the environment.
Local time formatting depends on your locale and settings.
Rounding to two decimals can hide very small timing changes.
If all durations are zero, a minimal inhale–exhale sequence is enforced.
The breathline shows a normalized level, not airflow or volume.

Edge cases & error sources

Extremely short durations may make cues hard to perceive.
Beep frequency below audibility or muted system volume yields silent transitions.
Clipboard or download permissions can block copy/save actions.
Denied wake lock allows the screen to sleep during sessions.
Heavy system load can delay animations slightly between frames.
Locale clocks crossing midnight shift the “Start” time in the timeline.
Browser restrictions may limit vibration or audio without user gesture.
Closing the tab resets state and clears in‑memory history.
Chart rendering may be skipped if the visual engine is unavailable.
Changing tabs disposes inactive charts and recreates them when reopened.

Step‑by‑Step Guide

Breathing cycles convert phase durations into a clear pace and timeline.

Choose a preset or select Custom.
Enter inhale, optional holds, and exhale in seconds.
Set Session length in minutes; use 0 for open‑ended.
Optionally set a Countdown and enable cues.
Press Start, breathe with the ring, and watch the pace.
Pause or Stop anytime; copy or download your timeline if useful.

Example: 4 / 0 / 6 / 0 produces 10 s cycles at 6.00 bpm. Practice ends when the session timer reaches zero.

FAQ

Is my data stored?

No. Calculations, timeline, copies, and downloads happen on your device. Nothing is sent to a server.

Clipboard and file actions may prompt for permission.

How accurate is the BPM?

BPM is exact for the entered durations: it is 60 divided by the sum of all phases. Visual easing does not change timing.

What units and formats are used?

Seconds for phases, minutes for session length, BPM as a number with two decimals, local time strings in the timeline.

Can I use it without sound or vibration?

Yes. Set audio volume to 0 and turn off vibration. The visual ring remains fully usable.

Does it work offline?

The pacing logic is local, but visuals may rely on a charting script. If unavailable, the session still runs without charts.

How do I pace 4 7 8 breathing?

Pick the 4‑7‑8 preset or set inhale 4 s, hold after inhale 7 s, exhale 8 s, and hold after exhale 0 s.

What does a “hold” stage do?

It inserts a pause after inhale or exhale. Holds lengthen the cycle and lower BPM while keeping the same in‑out ratio.

Why did my session end early?

When the elapsed time reaches the session length, the run stops automatically. Set session length to 0 if you want an open‑ended practice.

Troubleshooting

No sound: raise audio volume in the app and system settings.
No vibration: ensure device supports haptics and permission is granted.
Screen sleeps: enable Prevent sleep and keep the page active.
Copy fails: allow clipboard access when prompted.
Downloads missing: check your downloads folder or pop‑up settings.
Charts not visible: continue the session; visuals may be unavailable in this environment.

If Start is disabled, ensure the total cycle time is greater than zero by setting at least one phase above 0 s.

Glossary

Breaths per minute (BPM): Number of full inhale‑to‑exhale cycles per minute.
Cycle length: Sum of inhale, holds, and exhale durations.
Hold after inhale: Pause with lungs full before exhaling.
Hold after exhale: Pause with lungs empty before inhaling.
Countdown: Delay before the first inhale to get ready.
Easing: Animation curve for the visual ring pacing.
Wake lock: Request to keep the screen from sleeping.