VITALSee the range for your age
Median 5-minute SDNN
Middle half of that group
Enter your age and sex to see the band for that group. The chart below is the full published table.
Everything is worked out in your browser. Nothing you enter leaves this page or is saved.
The chart
These figures are SDNN, the standard deviation of the time between normal heartbeats, in milliseconds. Voss and colleagues measured a 5-minute ECG, taken lying down after 5 to 10 minutes of rest, in 1,906 healthy adults from the KORA S4 study in Augsburg, Germany. The table is the median and the middle half of each group, which is the 25th to 75th percentile, from the paper’s supporting tables. The study gives no figures under 25 or over 74, so this page does not fill any in.
| Age | Sex | People | Median | Middle half |
|---|---|---|---|---|
| 25 to 34 | Women | 208 | 44.9 ms | 35.4 to 58.1 ms |
| 35 to 44 | Women | 259 | 40.2 ms | 32.9 to 53.7 ms |
| 45 to 54 | Women | 158 | 35.5 ms | 26.5 to 44.5 ms |
| 55 to 64 | Women | 95 | 29.0 ms | 22.8 to 35.2 ms |
| 65 to 74 | Women | 62 | 26.0 ms | 18.7 to 32.5 ms |
| 25 to 34 | Men | 330 | 46.0 ms | 36.4 to 58.9 ms |
| 35 to 44 | Men | 292 | 42.6 ms | 32.3 to 53.1 ms |
| 45 to 54 | Men | 235 | 34.5 ms | 26.1 to 44.3 ms |
| 55 to 64 | Men | 183 | 29.9 ms | 22.0 to 39.3 ms |
| 65 to 74 | Men | 84 | 26.5 ms | 20.1 to 35.4 ms |
Middle half means the 25th to 75th percentile. SDNN is in milliseconds. A quarter of each group sat below the lower figure, and a quarter sat above the higher one.
Apple Watch uses SDNN, on a different recording
Apple Health records heart rate variability as SDNN, the same metric this chart uses. Apple’s developer documentation names the quantity heartRateVariabilitySDNN. The match stops at the name. This study used a 5-minute ECG in a clinic, lying down, after a short rest. Apple Watch takes shorter samples while you are still, through the day and overnight. A number from your watch is only a loose comparison with the table.
A chart of RMSSD, or of 24-hour recordings, is a different measurement again. What is a good HRV? explains why those numbers do not line up.
Your own trend matters more
Healthy people spread widely around these medians, and one reading moves with sleep, stress, training, illness, breathing and the time of day. The useful comparison is with your own usual over days and weeks. A figure outside the middle half is common, including among the healthy adults in this study. This is not medical advice, and it does not diagnose or treat anything.
In Vital
Vital compares your HRV with your own usual, rather than with an age table. The Heart page shows your readings from Apple Health and whether today is above, near or below your usual. When your watch records it, the Sleep page shows your overnight HRV too. HRV is one of the two readings the Readiness card waits for each morning.
Get Vital for iPhoneCommon questions
What is a normal HRV for my age?
There is no single normal number. For healthy women aged 25 to 34, this study reports a median 5-minute SDNN of 44.9 ms, and a middle half from 35.4 to 58.1 ms. Medians are lower in the older groups. The study covers ages 25 to 74 and reports women and men separately.
Does this match Apple Watch HRV?
Apple Watch reports HRV as SDNN, the metric in this chart. The study used a 5-minute ECG taken lying down after a short rest. Apple Watch takes shorter samples while you are still, including overnight, so a watch reading is only a loose comparison with these figures.
Why are women and men shown separately?
The study published women and men separately, and this page uses those groups as published. For this short-term SDNN measure, the paper reports no significant difference between women and men in these age bands.
Does the page save what I enter?
No. The lookup runs in your browser. Your age and HRV are not sent anywhere and are not saved.
Vital gives general information about fitness and wellbeing. It is not medical advice, and it does not diagnose or treat any condition. Your own trend matters more than a population average. If you are worried about your heart, speak to a GP.