HeartMath
HRV Interpreter

Powered by HeartMath South Africa

Transform emWave Pro Plus assessment data into clear, meaningful interpretations — for coaches, practitioners, and the people they support.

What this tool does

This app takes the numerical output from both emWave Pro Plus HRV assessments and generates plain-language and professional interpretations, printable client reports, and progress tracking over time.

No data is stored. Print your report before leaving the page.

The two assessments

1-minute deep breathing

A challenge test. Measures maximum vagal response capacity. Includes age- and sex-adjusted reference ranges.

5-minute HRV assessment

A resting measure. Captures frequency-domain variables including VLF. Values tracked as trajectory markers over time.

Before you begin — assessment conditions

Client seated comfortably, backrest at no more than 15 degrees. Feet flat on the floor.
No heavy exercise, caffeine, or smoking for at least 1 hour prior. No heavy meal within 1.5 hours.
1-minute assessment: breathe as deeply as comfortably possible — 5 seconds in, 5 seconds out. A practice session is recommended for first-time clients.
5-minute assessment: sit quietly, eyes open, no reading or intense mental activity.
Take repeated measures at the same time of day where possible to minimise circadian variation.
Medications that affect autonomic function can alter results — note when interpreting.

For use by certified HeartMath coaches and trained practitioners.
Not a diagnostic tool. Requires emWave Pro Plus hardware and software.

HeartMath HRV Interpreter

Client details
Enter values from the printed emWave Pro Plus reports. Reference ranges for the 1-minute assessment are already age- and sex-adjusted — enter them exactly as shown. The 5-minute assessment does not include printed reference ranges; values are tracked as trajectory markers over time.
1-minute deep breathing assessment challenge test · age-adjusted refs
Reference ranges from report (enter as printed)
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Measured values
5-minute HRV assessment resting · trajectory markers
Measured values
Client details
Enter SDNN, RMSSD, MHRR, Coherence and Heart Rate from two assessments at different points in time. Use the same assessment type for both readings. MHRR is only available from the 1-minute assessment.
Baseline reading
Current reading
Heart rate variability (HRV)
Your heart doesn't beat like a metronome — and that's a good thing. The small variations in timing between each beat are a sign that your nervous system is flexible and responsive. The emWave Pro Plus compares your 1-minute results against a reference range established for people of your age and sex. Sitting within or above that range indicates healthy adaptability; falling below it suggests your nervous system may need more support.
MHRR — the wave your heart makes
During the 1-minute assessment, your heart rate rises and falls with each breath cycle. MHRR measures the average size of that wave — the difference between the highest and lowest heart rate in each 10-second cycle. A larger wave means your vagus nerve is generating a strong, responsive signal. Values at the bottom of or below the reference range are a meaningful warning sign worth taking seriously.
SDNN — your nervous system reserve
SDNN reflects the overall capacity of your autonomic nervous system. Your report includes a reference range for your age and sex. A reading within that range means your reserve is where it should be for someone of your profile. A reading below it suggests your system is working with less capacity than is typical.
RMSSD — your recovery response
RMSSD measures how quickly your nervous system can shift into a calm, restorative state. It reflects the strength of your vagus nerve — the main pathway your brain uses to signal safety to the body. Below range suggests your body is taking longer to come down from stress than is typical. Very low RMSSD can indicate parasympathetic burnout — a more advanced stage of stress than simple anxiety.
Coherence — rhythm and order
Coherence measures how smooth and ordered your heart rhythm pattern is. When you breathe slowly and bring attention to the heart, a high-coherence pattern emerges — heart, brain, and nervous system come into sync. The scale runs from 50 to 100%. Coherence is a learned skill — most people shift their patterns meaningfully with practice regardless of where they start.
Mean IBI — your heart's natural pace
IBI stands for inter-beat interval — the average time between heartbeats. As your nervous system settles through practice, resting heart rate tends to come down and IBI rises — improvement here is a meaningful sign the body is finding more ease.
Total power, VLF, LF, and HF (5-minute)
These frequency-domain measures look at how your heart rhythm fluctuates at different speeds. High frequency (HF) reflects calming activity driven by breathing. Low frequency (LF) includes the heart's coherence rhythm at ~0.1 Hz. Very low frequency (VLF) reflects the intrinsic rhythm of the heart — healthy VLF levels are a positive sign. Total power is the sum of all this variability.