Resting Heart Rate by Age: Normal Range, Dangers & ER Thresholds

You’ve probably checked your pulse at some point and wondered if that number is okay. That number — your resting heart rate — is one of the simplest health signals you can track, but it’s also easy to misinterpret. This guide walks through what normal looks like at different ages, when a high or low reading becomes a real concern, and exactly when you should call for help.

Normal resting heart rate (adults): 60 to 100 beats per minute (bpm) ·
Optimal resting heart rate (healthy adults): 55 to 85 bpm ·
Bradycardia threshold: Below 60 bpm ·
Tachycardia threshold: Above 100 bpm ·
Heart rate for well-trained athletes: 40 to 60 bpm

Key facts at a glance

Six critical numbers that define the boundaries of normal and risky heart rates, drawn from major medical institutions.

What is a normal resting heart rate by age?

Age is the single biggest factor in what counts as “normal” for your resting heart rate. A newborn’s heart beats twice as fast as a healthy adult’s, and your own rate gradually shifts as you get older. Cleveland Clinic lists typical resting heart rates by age, including 100 to 205 bpm for newborns and 60 to 100 bpm for adults 18 and older (Cleveland Clinic cardiology department).

Resting heart rate for adults (18+)

• The American Heart Association defines a normal resting heart rate as 60 to 100 bpm when sitting or lying calmly and feeling well (American Heart Association clinical guidelines).
• Harvard Health says the range for most healthy adults is 55 to 85 bpm (Harvard Health heart health division).
• Adults aged 18 to 30 often average in the low 80s bpm, while those 50 to 80 average in the low 70s (GoodRx health analytics team).
• Well-trained athletes can have resting rates of 40 to 60 bpm without any problems (Harvard Health).

The implication: staying below 90 bpm at rest is a reasonable target for most adults, not just athletes.

Resting heart rate for children (ages 6‑17)

• School‑age children (5–12 years): typical range 75 to 118 bpm (Cleveland Clinic).
• Adolescents (13–17 years): 60 to 100 bpm (Cleveland Clinic).

Children’s hearts have higher resting rates because their bodies are smaller and metabolically active. The pattern: pre‑teen ranges cluster in the 70–110 bpm zone, then settle into adult numbers by the late teens.

Resting heart rate for older adults (65+)

• Older adults stay within the 60–100 bpm range but often trend lower — the average for ages 61–70 is about 73.0 bpm (Healthline analysis of population data).
• Medications like beta‑blockers can lower resting heart rate further.

Is a resting heart rate of 120 normal?

A reading of 120 bpm while you’re sitting still is above the normal threshold and counts as tachycardia. But context matters — temporary spikes happen for many reasons.

When 120 bpm may be normal

• After caffeine, anxiety, or a fever, heart rate can temporarily jump into the 100s (NHS cardiology guidance).
• Dehydration also raises heart rate as your heart works harder to pump less fluid.
• If you’ve just exercised or walked up stairs, a reading of 120 is normal during recovery.

When 120 bpm indicates tachycardia

• The NHS states that a normal resting heart rate is 60 to 100 bpm, and that supraventricular tachycardia can raise the heart rate suddenly above 100 bpm even at rest (NHS).
• Cleveland Clinic says to seek medical attention right away if heart rate is above 100 bpm with symptoms such as palpitations, shortness of breath, chest pain, or dizziness (Cleveland Clinic).
• GoodRx says a heart rate that stays over 100 bpm for hours is usually not normal, and a sudden unexpected jump above 120 bpm could indicate trouble (GoodRx medical review team).

What to do if your resting heart rate is 120

• Sit quietly for five minutes and retake your pulse. If it remains above 100, note any other symptoms.
• If you have chest pain, shortness of breath, or feel faint, call 911 immediately (American Heart Association emergency guidelines).
• If you have no symptoms but the reading persists for days, schedule an appointment with your doctor.

The pattern: a single high reading after coffee is not an emergency, but a persistent 120 bpm at rest needs medical attention.

Is a resting heart rate of 45 too low?

Forty‑five beats per minute is below the standard threshold of 60 bpm, but whether it’s dangerous depends on who you are and how you feel.

Bradycardia definition and causes

• Bradycardia is a resting heart rate below 60 bpm (Mass General Brigham cardiology).
• Causes include: sick sinus syndrome, heart block, hypothyroidism, certain medications, and electrolyte imbalances.

When low heart rate is normal (athletes)

• Well‑trained athletes often have resting rates of 40 to 60 bpm because their hearts pump more blood per beat (Harvard Health).
• If you’re an endurance athlete with a heart rate of 45 and feel fine, it’s a sign of efficiency — not illness.

Symptoms of problematic bradycardia

• Cleveland Clinic says to seek medical attention right away if heart rate is below 35 to 40 bpm (Cleveland Clinic).
• If a rate of 45 bpm comes with dizziness, fatigue, fainting, or shortness of breath, it may be dangerous and requires evaluation (American Heart Association).

The implication: symptoms matter more than the number; a symptom-free 45 bpm in a non-athlete still warrants a doctor’s check.

What is an unsafe resting heart rate?

Both ends of the heart rate spectrum have red lines, but numbers alone don’t tell the full story — symptoms are the real trigger for action.

Dangerously high heart rate thresholds

• Resting heart rate persistently above 120 bpm is generally considered unsafe (GoodRx).
• Above 100 bpm with symptoms (chest pain, SOB, fainting) is an emergency (American Heart Association).

Dangerously low heart rate thresholds

• Resting rate below 40 bpm (especially with symptoms) is considered dangerous (Cleveland Clinic).
• For non‑athletes, rates below 50 bpm warrant a conversation with a doctor if risk factors are present.

Symptoms that signal emergency

• Cleveland Clinic says to seek medical attention right away if heart rate is below 35 to 40 bpm or above 100 bpm with symptoms such as palpitations, shortness of breath, chest pain, or dizziness (Cleveland Clinic).
• The American Heart Association says to call 911 if heart rate is suddenly very high or very low for you, especially with chest pain, shortness of breath, dizziness, or fainting (American Heart Association).

The trade‑off: a rate of 118 bpm with no symptoms is less urgent than a rate of 95 bpm with crushing chest pain. Always prioritise symptoms over the number.

The catch: your personal baseline matters — a sudden change from 70 to 110 bpm can be more telling than a static 110 bpm.

When should I go to the hospital for heart rate concerns?

Knowing when to head to the ER can save valuable time. These are the clearest thresholds from national guidelines.

Heart rate 122 bpm: emergency or not?

• NHS guidelines advise immediate emergency help for SVT if the episode lasts longer than usual or if a fast heartbeat occurs with shortness of breath, chest pain, or feeling faint (NHS emergency care guidelines).
• Go to ER if heart rate >120 bpm with chest pain, breathlessness, or fainting (NHS).

Heart palpitations and emergency room visit

• GoodRx recommends prompt medical review for palpitations lasting more than a few minutes, shortness of breath, or dizziness (GoodRx clinical review).
• Heart palpitations with loss of consciousness require an ambulance.

Bradycardia and when to seek help

• Resting heart rate 45 bpm with symptoms (dizziness, fatigue, fainting) warrants emergency evaluation (American Heart Association).
• If no symptoms, a primary care visit is appropriate to rule out underlying causes.

The implication: your symptoms, not just the number on the monitor, drive the decision to go to the ER.

“A normal resting heart rate for adults ranges from 60 to 100 beats per minute. If your heart rate is consistently above 100 bpm or below 60 bpm and you have symptoms, you should see a doctor.”

— Cleveland Clinic cardiology department

“Call 911 if your heart rate is suddenly very high or very low for you, especially if you also have chest pain, shortness of breath, dizziness, or fainting.”

— American Heart Association emergency guidelines

Normal resting heart rate by age — comparison table

Seven age groups, one clear pattern: younger equals faster, and the transition to adult numbers happens during adolescence.

The pattern: heart rate declines steadily from birth through adolescence, then stabilises in adulthood.

Upsides and downsides of tracking your resting heart rate

What’s clear and what’s still uncertain

For the average adult who wants to stay out of the ER, the choice is clear: use your resting heart rate as a rough gauge, but let symptoms — not numbers — drive your decisions. A rate of 95 bpm with chest pain is an emergency; a rate of 115 bpm after a stressful day with no other symptoms is a conversation with your GP.

Frequently asked questions