Your target heart rate range is the number of beats per minute your heart should reach during exercise to get cardiovascular benefits without overworking your body. For most people, that range falls between 50% and 85% of their maximum heart rate, with the exact percentage depending on how intense the workout is. The American Heart Association defines moderate-intensity exercise as 50% to 70% of your max, and vigorous exercise as 70% to 85%.
How to Find Your Maximum Heart Rate
Your target range is built on one number: your estimated maximum heart rate. The most common formula is simply 220 minus your age. If you’re 40 years old, that gives you an estimated max of 180 beats per minute (bpm). It’s simple, but it’s not especially precise. Research shows the 220-minus-age formula can be off by as much as 9 bpm on average. It tends to overestimate max heart rate in younger adults and underestimate it in older adults, landing in a reasonably accurate range only for people in their 30s.
A more accurate alternative is the Tanaka formula: 208 minus 0.7 times your age. For that same 40-year-old, the result is 180 bpm (the two formulas happen to converge near age 40), but for a 25-year-old the Tanaka formula gives 190 bpm versus 195 from the traditional formula. The difference matters more at the extremes of age. Neither formula is perfect, but the Tanaka formula consistently produces smaller errors across a wider range of ages and fitness levels.
What the Percentages Actually Mean
Once you have your estimated max, you multiply it by a percentage to get the boundaries of your target range. A 50-year-old with an estimated max of 170 bpm would aim for 85 to 119 bpm during moderate exercise (50% to 70%) and 119 to 145 bpm during vigorous exercise (70% to 85%). Those two bands cover the full target heart rate range the AHA recommends.
Within that broad range, exercise science breaks effort into five zones:
- Zone 1 (50% to 60%): Easy effort, good for warm-ups, cool-downs, and recovery days. You can hold a full conversation comfortably.
- Zone 2 (60% to 70%): Light effort that builds endurance over longer sessions. Talking is possible but you may pause to catch your breath.
- Zone 3 (70% to 80%): Comfortably hard. Conversation drops off as breathing intensifies. This zone builds both strength and cardiovascular endurance.
- Zone 4 (80% to 90%): Hard effort that improves speed and power. Talking takes real effort. Limit workouts here to once or twice a week.
- Zone 5 (90% to 100%): Maximum effort. You’re gasping, not talking. This zone forces your heart to work at peak capacity and recruits fast-twitch muscle fibers. It’s unsustainable for more than short bursts.
Most general fitness goals are served by spending the bulk of your workout time in Zones 2 and 3, with occasional pushes into Zone 4. Zone 5 is typically reserved for interval training or competitive athletes.
The Karvonen Method: A More Personalized Calculation
The basic percentage method treats everyone with the same max heart rate identically, but two people the same age can have very different resting heart rates. Someone with a resting pulse of 55 bpm has more cardiovascular headroom than someone resting at 80 bpm. The Karvonen method (also called the heart rate reserve method) accounts for this difference.
Here’s how it works. First, subtract your resting heart rate from your maximum heart rate. The result is your heart rate reserve, the total range your heart can work within. Then multiply that reserve by your desired training percentage, and add your resting heart rate back. So a 45-year-old with a resting heart rate of 65 bpm and an estimated max of 175 bpm has a heart rate reserve of 110 bpm. To find the low end of a moderate target (60% of reserve): 110 × 0.60 = 66, plus 65 = 131 bpm. To find the high end (80% of reserve): 110 × 0.80 = 88, plus 65 = 153 bpm. That personalized range of 131 to 153 bpm reflects their actual fitness baseline better than the simpler formula would.
In cardiac rehabilitation programs, patients commonly aim for 60% to 80% of heart rate reserve plus their resting heart rate. For general fitness, you can plug in whatever zone percentage you’re targeting.
How to Check Your Heart Rate During Exercise
The easiest modern option is a chest strap or wrist-based heart rate monitor, which gives you a continuous reading. But you can also check manually by finding your pulse at one of two spots.
For a wrist (radial) pulse: turn one palm face-up and place the middle three fingers of your other hand on the groove just below where your thumb meets your wrist. Press firmly until you feel the beat. For a neck (carotid) pulse: place your index and middle fingers in the groove under your jawline, next to your windpipe. Press firmly.
Count the beats for 30 seconds and double the number for your beats per minute. If you want a quicker check mid-workout, count for 10 seconds and multiply by six. The 30-second count is more accurate, but the 10-second shortcut works well enough when you don’t want to stop moving for long.
When Heart Rate Targets Don’t Apply Normally
Certain medications change the math entirely. Beta-blockers, commonly prescribed for high blood pressure and heart conditions, lower both resting and maximum heart rate. If you take one, you may never reach the target range calculated from standard formulas, even when you’re working hard. Rather than chasing a number your medication won’t let you hit, you can use perceived exertion instead: rate your effort on a scale of 1 to 10, where moderate exercise feels like a 5 or 6 and vigorous feels like a 7 or 8.
Fitness level also shifts the picture. A well-trained endurance athlete may have a resting heart rate in the low 40s or 50s, which makes the Karvonen method especially useful since a simple percentage of max heart rate would underestimate how hard they actually need to work. On the other end, someone just starting to exercise may find that even a brisk walk pushes them into Zone 3. That’s normal. As cardiovascular fitness improves over weeks and months, the same activity will register at a lower heart rate, and you’ll need to work harder to reach the same zone.
Putting Your Target Range to Use
Knowing your target heart rate range turns vague advice like “exercise at moderate intensity” into something measurable. Start by estimating your max heart rate with either formula. If you know your resting heart rate (check it first thing in the morning before getting out of bed, averaged over a few days), use the Karvonen method for a more tailored number. Pick a zone that matches your goal: Zone 2 for steady endurance building, Zone 3 for general fitness, Zone 4 for performance gains.
Check your heart rate a few minutes into your workout and adjust your pace up or down. Over time, you’ll develop an intuitive sense of what each zone feels like, and the numbers become a useful confirmation rather than something you need to monitor constantly.