HRV Score Interpreter
Paste your morning RMSSD reading from any wearable and instantly get a 0-100 readiness score, a percentile compared to people your age, and a plain-English verdict on whether to train hard or rest. Nothing uploaded.
HRV Score
0-100 scale - 70+ is high, 50-69 moderate, below 50 low
Age-Normed Comparison
7-Day Rolling Trend
What affects your HRV?
- Sleep quality: Poor or short sleep suppresses the nervous system overnight and lowers the next morning's HRV significantly.
- Alcohol: Even one or two drinks can drop RMSSD by 10-20 ms the following morning as the body metabolises alcohol.
- Overtraining: A string of hard sessions without rest accumulates fatigue; HRV will trend down over days or weeks.
- Illness: Infection activates the immune system and raises sympathetic tone, often causing a sudden HRV dip before symptoms appear.
- Stress: Psychological stress raises cortisol and shifts balance toward the fight-or-flight branch, reducing HRV.
- Breathing and hydration: Slow diaphragmatic breathing and good hydration both support higher HRV readings.
Heart Rate Variability as a Training Tool
How RMSSD Scoring Works
This calculator converts your RMSSD milliseconds into a 0-100 score using a logarithmic formula similar to WHOOP's system. Lower RMSSD (20-30 ms) gets a low score around 30, while higher RMSSD (60+ ms) scores in the 70-80 range. The percentile compares your reading to published norms for your age and sex group, showing how you rank against the general population.
HRV is Not a Medical Diagnostic
A low HRV reading might suggest fatigue or early illness, but it is not a diagnosis. One dip does not mean you are sick or overtrained. Watch the 7-day trend instead - patterns matter more than single readings. This tool is designed for self-tracking and training decisions, not replacing a doctor's assessment. If you have persistent symptoms, seek medical advice.
FAQ
Is HRV a medical diagnostic tool?
No. HRV is a self-tracking metric for training recovery and stress, not a diagnostic tool. A single low reading does not mean you are sick or unfit, and a high reading does not replace a doctor's visit. If you have persistent symptoms, see a healthcare provider. This tool provides context for your reading, nothing more.
Why does my HRV vary so much day to day?
HRV responds to sleep quality, caffeine, alcohol, stress, illness, and hard training. A poor night's sleep can drop RMSSD by 10-20 ms. A virus that hasn't yet shown symptoms can dip HRV before you feel sick. The 7-day rolling trend matters more than any single day - watch for patterns, not panic about one low reading.
Can I use this to decide whether to exercise?
Treat it as one data point among many. A low HRV reading might suggest taking a light day, but if you feel rested and have planned training, a single metric should not override how you feel. Combine HRV with sleep hours, resting heart rate, mood, and perceived exertion for the full picture.