Heart rate 103 - good or bad?
It depends on who was measured and what they were doing. Here is the short answer for 103 beats per minute:
Adult at rest
Elevated (tachycardia)A resting heart rate of 103 bpm is above 100 — that is called tachycardia. It is often a temporary reaction (caffeine, stress, fever, recent activity), but if it stays above 100 at rest it should be checked.
Adult details →Child at rest
Normal for some agesA heart rate of 103 bpm is within the normal resting range for: newborn (0–1 month), infant (1–11 months), toddler (1–2 years), preschool (3–4 years), child (5–6 years) and child (7–9 years). It is above it at 10+ yr.
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 70 to 190 bpm; 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.
103 bpm during exercise
During exercise a higher pulse is expected. This table shows which training zone 103 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) | 103 bpm is | Training zone |
|---|---|---|---|
| 20 | 200 bpm | 52% | Zone 1 · Very light |
| 30 | 190 bpm | 54% | Zone 1 · Very light |
| 40 | 180 bpm | 57% | Zone 1 · Very light |
| 50 | 170 bpm | 61% | Zone 2 · Light |
| 60 | 160 bpm | 64% | Zone 2 · Light |
| 70 | 150 bpm | 69% | Zone 2 · Light |
How the zones work: Heart Rate Zones: The 5 Training Zones by Age.
Check another reading
Nearby values
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.