Heart Rate Variability: Time Domain (Task Force 1996)
Heart rate variability time-domain measures from RR intervals: SDNN, RMSSD, NN50, pNN50 and the triangular index, as the 1996 Task Force defines them.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- RR intervals in ms, one per line
- 800, 860, 800, 860, 800
Result: RMSSD 60 ms, SDNN 32.86 ms
The tool opens with these values already filled in. Replace them with your own.
What you enter
- RR intervals in ms, one per line
- Flag a change above this percent
How this is calculated
Citation
Task Force of the ESC and NASPE. Heart rate variability: standards of measurement, physiological interpretation and clinical use. Circulation 1996;93:1043-1065, Table 1 (time-domain measures). Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.