Heart rate 100 - good or bad?
It depends on who was measured and what they were doing. Here is the short answer for 100 beats per minute:
Adult at rest
NormalA resting heart rate of 100 bpm is within the normal adult range of 60–100 bpm.
Adult details →Child at rest
Normal at every child ageA heart rate of 100 bpm is within the normal resting range at every child age from newborn to 9 years (awake and calm).
Child details →Who was measured?
Why the answer changes with age
Small hearts pump less blood per beat, so they have to beat faster. A newborn's normal resting pulse can be anywhere from 100 to 190 bpm (MedlinePlus lists 70–190, but in a newborn a rate below 100 needs prompt assessment); by age 10 it settles into the adult range of 60–100 bpm. A pulse of 150 can be perfectly normal for a three-month-old and worrying in an adult at rest. The same rule holds across mammals: a mouse's heart beats around 500 times a minute, an elephant's about 30.
100 bpm during exercise
During exercise a higher pulse is expected. This table shows which training zone 100 bpm corresponds to, based on the common estimate of maximum heart rate (220 minus age). Individual maximums can differ by 10–20 bpm.
| Age | Est. max (220 − age) | 100 bpm is | Training zone |
|---|---|---|---|
| 20 | 200 bpm | 50% of max | Zone 1 · Very light |
| 30 | 190 bpm | 53% of max | Zone 1 · Very light |
| 40 | 180 bpm | 56% of max | Zone 1 · Very light |
| 50 | 170 bpm | 59% of max | Zone 1 · Very light |
| 60 | 160 bpm | 63% of max | Zone 2 · Light |
| 70 | 150 bpm | 67% of max | Zone 2 · Light |
How the zones work: Heart Rate Zones: The 5 Training Zones by Age.
Check another reading
Nearby values
Sources: American Heart Association: All About Heart Rate · MedlinePlus: Pulse · AHA 2020 guidelines, neonatal resuscitation · ACSM position stand on exercise intensity (2011)
This page explains a single reading in general terms. It is not a diagnosis. Heart rate alone cannot tell whether the rhythm is regular or whether the heart is healthy — if you are worried, talk to a doctor.