Your target heart rate is the ideal range of heartbeats per minute to aim for during exercise. For moderate-intensity activity, that range is 50% to 70% of your maximum heart rate. For vigorous exercise, it’s 70% to 85%. Knowing these numbers helps you get the most out of a workout without pushing too hard or coasting too easy.
How to Find Your Maximum Heart Rate
Every target heart rate calculation starts with your estimated maximum heart rate. The simplest formula is 220 minus your age. A 40-year-old, for example, has an estimated max of 180 beats per minute (bpm). A more refined formula, developed by researcher Hirofumi Tanaka, uses 208 minus 0.7 times your age, which gives that same 40-year-old a max of 180 bpm but becomes more accurate at younger and older ages where the two formulas diverge.
Neither formula is perfect. Research on recreational marathon runners found that the standard 220-minus-age formula overestimated max heart rate by about 5 bpm in women and underestimated it by about 3 bpm in men. The Tanaka formula performed better for men but still overestimated for women by a similar margin. These are population averages, so your true maximum could be 10 to 15 beats higher or lower than any formula predicts. If you wear a chest strap or wrist monitor during an all-out effort, you’ll get a more personal number to work from.
Target Heart Rate by Age
Using the 220-minus-age formula and the American Heart Association’s recommended range of 50% to 85% of maximum, here’s what the numbers look like at different ages:
- Age 25: Max 195 bpm, target zone 98–166 bpm
- Age 30: Max 190 bpm, target zone 95–162 bpm
- Age 35: Max 185 bpm, target zone 93–157 bpm
- Age 40: Max 180 bpm, target zone 90–153 bpm
- Age 45: Max 175 bpm, target zone 88–149 bpm
- Age 50: Max 170 bpm, target zone 85–145 bpm
- Age 55: Max 165 bpm, target zone 83–140 bpm
- Age 60: Max 160 bpm, target zone 80–136 bpm
- Age 65: Max 155 bpm, target zone 78–132 bpm
- Age 70: Max 150 bpm, target zone 75–128 bpm
These ranges are broad on purpose. The lower end (50% to 70%) covers moderate activity like brisk walking or an easy bike ride. The upper end (70% to 85%) covers vigorous efforts like running, fast cycling, or high-intensity interval training.
A More Personalized Calculation
The basic percentage method treats everyone the same, but two 40-year-olds can have very different fitness levels. The Karvonen method accounts for this by factoring in your resting heart rate. Here’s how it works:
First, find your resting heart rate by counting your pulse for 60 seconds first thing in the morning, before getting out of bed. A typical resting heart rate falls between 60 and 80 bpm, though well-trained athletes can sit in the 40s or 50s. Next, subtract your resting heart rate from your maximum heart rate. This number is your heart rate reserve, the usable range your heart has to work with.
To find a specific target, multiply your heart rate reserve by the percentage you want, then add your resting heart rate back. For a 40-year-old with a resting heart rate of 65 bpm aiming at 60% intensity: (180 – 65) × 0.60 + 65 = 134 bpm. Compare that to the basic method, which gives 108 bpm at 60%. The Karvonen method produces a higher, more realistic target because it recognizes that a fit person with a low resting heart rate has more capacity to push.
What Each Intensity Zone Does
The broad “50% to 85%” range contains several distinct training zones, and each one produces different benefits.
At 50% to 60% of your max, you’re in a light effort zone. This is a comfortable walking pace where you can hold a full conversation without any trouble. It’s a good starting point if you’re new to exercise or recovering from illness.
At 60% to 70%, you enter moderate intensity (often called zone 2). You can still talk, though you might pause mid-sentence to catch your breath. Your body preferentially burns stored fat for fuel at this level, and longer sessions here build aerobic endurance. This is the intensity most associated with general cardiovascular health.
At 70% to 80%, the effort shifts to vigorous. Conversation becomes choppy. Your body starts relying more on carbohydrate stores for energy, and you’re building both endurance and speed. This is where many running and cycling training plans spend the bulk of their time.
At 80% to 90%, you’re in high-intensity territory. Talking takes real effort. These intervals boost speed, power, and your body’s ability to process oxygen at high workloads. At 90% to 100%, you’re at near-maximum effort, breathing too hard to speak. This level strengthens fast-twitch muscle fibers and forces your heart to work at peak capacity, but it’s only sustainable for short bursts.
If weight loss is a primary goal, spending most of your workout time in the lower zones (up to about 70% of max) is generally more practical. You can sustain the effort longer, burn more total calories per session, and rely more on fat as fuel. Higher zones burn calories faster per minute but are harder to maintain, and the fuel mix shifts toward carbohydrates and protein.
Factors That Shift Your Heart Rate
Several things can raise or lower your heart rate independent of how hard you’re exercising, making your target zone a moving target on certain days.
Beta-blockers, commonly prescribed for high blood pressure, directly slow your heart rate. If you take one, your heart rate during exercise will be significantly lower than the formulas predict, and the standard percentage-based zones won’t apply to you. Other medications that affect blood pressure or hydration, including diuretics, certain antidepressants, and stimulant medications, can also alter your heart rate response to exercise.
Heat and humidity raise heart rate because your body diverts blood to the skin for cooling. On a hot day, the same jog that keeps you at 140 bpm in cool weather might push you to 155 bpm. Dehydration compounds this effect. Caffeine, stress, poor sleep, and illness all push resting and exercise heart rates higher as well. If your numbers seem unusually high on a given day, it’s often smarter to follow how your body feels rather than chasing a specific number.
Tracking Without a Monitor
You don’t need a smartwatch or chest strap to gauge your intensity. The talk test is the simplest method: if you can speak in full sentences, you’re in the moderate zone. If you can only get out a few words between breaths, you’re in the vigorous zone. If you can’t talk at all, you’re near your max.
A more structured option is the Borg Rating of Perceived Exertion scale, which runs from 6 (no effort at all) to 20 (absolute maximum). A rating of 12 to 14 corresponds roughly to moderate intensity, the equivalent of 50% to 70% of max heart rate for most people. A rating of 15 to 17 maps to vigorous effort. The scale is deliberately designed so that multiplying your rating by 10 approximates your actual heart rate (a perceived exertion of 14 suggests roughly 140 bpm), though this relationship varies with age, fitness level, and medications.
For a quick manual pulse check during exercise, press two fingers lightly against the side of your neck or the inside of your wrist. Count the beats for 15 seconds and multiply by four. It’s not as precise as a monitor, but it’s close enough to tell you whether you’re in the right ballpark.