Heart rate and pulse rate are closely related but not technically the same thing. Your heart rate is the number of times your heart squeezes per minute. Your pulse is the number of times your arteries expand and contract in response to that squeezing. In most healthy people, the two numbers are identical, which is why they’re used interchangeably in everyday conversation. But there are specific situations where they can differ, and understanding why matters.
What Each One Actually Measures
Your heart rate is an electrical event. Each heartbeat is triggered by an electrical impulse that tells the heart muscle when to contract. To directly measure heart rate, a device needs EKG technology that detects and interprets those electrical signals.
Your pulse is a mechanical event, a pressure wave. When your heart contracts, it pushes blood into the aorta, which stretches the arterial wall and sends a compression wave rippling outward through every artery in your body. That wave travels fast enough to reach your wrist, roughly a meter from your heart, almost instantly. When you press two fingers against the inside of your wrist and feel a rhythmic throbbing, you’re not feeling your heart squeeze. You’re feeling your radial artery widen slightly each time that pressure wave passes through.
So heart rate is measured at the source (the heart’s electrical system), while pulse is measured downstream (the arteries responding to blood flow). For most people at rest, these produce the same number. A normal resting value for adults falls between 60 and 100 beats per minute, though well-trained athletes can sit closer to 40.
When Heart Rate and Pulse Don’t Match
The gap between heart rate and pulse becomes clinically meaningful in certain conditions. The most common example is atrial fibrillation, a type of irregular heart rhythm. During uncontrolled atrial fibrillation, the heart can beat so rapidly or erratically that some contractions are too weak to push enough blood into the arteries to generate a detectable pulse at the wrist. The heart squeezes, but the artery doesn’t expand. This creates what’s called a “pulse deficit,” where the heart rate counted by listening to the chest is higher than the pulse counted at the wrist.
Premature heartbeats (the sensation of a skipped beat or extra beat) can cause the same mismatch. If the heart contracts before it has filled with enough blood, that weak beat may not produce a pulse you can feel. Well-controlled atrial fibrillation, by contrast, should have no pulse deficit at all, meaning every heartbeat successfully transmits to the wrist.
What Your Wearable Is Actually Reading
Most fitness trackers and smartwatches don’t have EKG sensors. Instead, they shine green light into your skin and measure how the light absorption changes as blood pulses through your capillaries. This is called optical sensing, and it’s measuring your pulse, not your heart rate in the strict electrical sense.
Optical sensors are quite accurate during steady-state activity like jogging or cycling at a constant pace, where accuracy can reach above 90% and even approach 98% during sustained cycling. But they struggle during transitions in exercise intensity. When you suddenly speed up, the sensor tends to underestimate your rate. When you slow down, it tends to overestimate. During activities with lots of wrist movement, like circuit weight training, accuracy can drop as low as 35%. The sensor’s readings lag behind your actual rate until your body reaches a new steady state.
If your watch has a dedicated EKG feature (some newer models do), that mode is reading your heart’s electrical activity directly, giving you a true heart rate rather than a pulse-derived estimate.
Where to Check Your Pulse
The two easiest spots are the wrist and the neck. At the wrist, press your index and middle fingers on the inner side, just below the base of your thumb. At the neck, press gently beside your windpipe. Count the beats for 15 seconds and multiply by four.
Healthcare providers check pulses at several other locations depending on what they’re evaluating: the inner elbow, behind the knee, the top of the foot, and behind the ankle bone. These spots are useful for assessing blood flow to different parts of the body, not just counting beats. A weak or absent pulse in the foot, for example, can signal a circulation problem in the leg that has nothing to do with heart rate.
What Affects Pulse Strength
Your pulse rate and your pulse strength are two different things. Two people can both have a pulse of 70 beats per minute, but one person’s pulse feels bounding and strong while the other’s feels faint and thready. The strength of each pulse beat depends on how much blood the heart ejects with each contraction, which is influenced by three factors: how full the heart is before it squeezes, how forcefully the muscle contracts, and how much resistance the blood vessels are putting up.
Dehydration reduces the volume of blood returning to the heart, which means less filling before each contraction and a weaker pulse. High blood pressure increases the resistance the heart has to push against, which can also change pulse characteristics. Exercise, stress, caffeine, and thyroid hormones all increase both the rate and force of contraction, making the pulse faster and stronger simultaneously.
This is another reason pulse and heart rate aren’t perfectly interchangeable concepts. Heart rate tells you how often the heart beats. Pulse tells you how often and how strongly those beats arrive at a given artery, which carries additional information about circulation, blood volume, and vascular health that a simple heart rate number doesn’t capture.