❤️ Target Heart Rate Calculator
By ToolNimba Health Team · Reviewed by ToolNimba Editorial Review, fitness and exercise content · Updated 2026-06-19
This calculator gives a general estimate based on age and resting pulse, not a medical assessment. Estimated maximum heart rate formulas have a wide margin of error (roughly plus or minus 10 to 12 bpm), and your true zones depend on fitness, medication and health conditions. If you have a heart condition, take beta-blockers or other medication that affects heart rate, are pregnant, or are new to exercise, talk to a doctor before training to these numbers.
Enter your resting pulse to switch to the Karvonen (heart-rate-reserve) method, which is more personalised.
| Zone | Intensity | Target heart rate |
|---|
Your target heart rate is the beats-per-minute range you aim for during exercise to train at the right intensity for your goal. This calculator first estimates your maximum heart rate from your age, then breaks the effort into zones from 50% (very light) up to 85% (hard). Add your resting pulse and it switches to the more personalised Karvonen method. Enter your age and read off the zone that matches your workout, whether that is an easy recovery jog or a hard interval session.
What is the Target Heart Rate Calculator?
Your maximum heart rate (max HR) is the highest your heart can safely beat during all-out effort, and it falls slowly with age. The classic estimate is the Haskell formula, max HR = 220 - age, which is simple and widely used on gym machines. A more accurate fit to modern research is the Tanaka formula, max HR = 208 - 0.7 x age, which tends to give slightly higher numbers for older adults and slightly lower ones for the young. Both are population averages, so an individual can easily sit 10 to 12 bpm above or below the estimate.
Once you have a max HR, training zones are simply percentages of it. A 50 to 60% effort is a gentle warm-up, 60 to 70% builds aerobic base and is the classic 'fat burn' range, 70 to 80% is solid cardio that improves fitness, and 80 to 85% pushes toward your anaerobic threshold. Pegging zones to a percentage of max HR is quick, but it ignores how fit you already are: two people the same age get identical targets even if one is a couch potato and the other a marathoner.
The Karvonen method fixes that by using your heart-rate reserve (HRR), the gap between your maximum and your resting heart rate. The formula is target = ((max HR - resting HR) x intensity) + resting HR. Because a fitter person has a lower resting pulse, their reserve is larger and their zones shift, so the targets reflect their actual condition. To use it you need a good resting heart rate: take your pulse for a full minute first thing in the morning before getting out of bed, ideally averaged over a few days.
When to use it
- Setting an easy zone for recovery runs so you do not accidentally train too hard on rest days.
- Finding the 60 to 70% "fat burn" range for steady cardio and longer endurance sessions.
- Capping interval and threshold work at a safe upper limit (around 85% of max).
- Programming a heart-rate monitor, smartwatch or gym treadmill with zones tailored to your age and fitness.
How to use the Target Heart Rate Calculator
- Enter your age in years.
- Choose the maximum heart rate formula: Haskell (220 - age) or Tanaka (208 - 0.7 x age).
- Optionally enter your resting heart rate to switch to the Karvonen (heart-rate-reserve) method.
- Read your estimated max HR and the target beats-per-minute range for each training zone.
Formula & method
Worked examples
A 40-year-old wants their zones as a percentage of max heart rate (no resting pulse entered).
- Max HR = 220 - 40 = 180 bpm
- Zone 1 (50-60%): 180 x 0.50 = 90, 180 x 0.60 = 108, so 90-108 bpm
- Zone 2 (60-70%): 180 x 0.60 = 108, 180 x 0.70 = 126, so 108-126 bpm
- Zone 3 (70-80%): 180 x 0.70 = 126, 180 x 0.80 = 144, so 126-144 bpm
- Zone 4 (80-85%): 180 x 0.80 = 144, 180 x 0.85 = 153, so 144-153 bpm
Result: Max HR 180 bpm. Fat-burn zone 108-126 bpm, hard zone 144-153 bpm.
A 30-year-old with a resting heart rate of 60 bpm uses the Karvonen method.
- Max HR = 220 - 30 = 190 bpm
- Heart-rate reserve (HRR) = 190 - 60 = 130 bpm
- Zone 1 (50-60%): 130 x 0.50 + 60 = 125, 130 x 0.60 + 60 = 138, so 125-138 bpm
- Zone 2 (60-70%): 130 x 0.60 + 60 = 138, 130 x 0.70 + 60 = 151, so 138-151 bpm
- Zone 3 (70-80%): 130 x 0.70 + 60 = 151, 130 x 0.80 + 60 = 164, so 151-164 bpm
- Zone 4 (80-85%): 130 x 0.80 + 60 = 164, 130 x 0.85 + 60 = 170.5, so 164-171 bpm
Result: Max HR 190 bpm, HRR 130. Cardio zone 151-164 bpm, hard zone 164-171 bpm.
Training zones as a percentage of maximum heart rate
| Zone | Intensity (% of max HR) | What it feels like | Main benefit |
|---|---|---|---|
| Zone 1 | 50-60% | Very light, can chat easily | Warm-up, recovery |
| Zone 2 | 60-70% | Light, comfortable | Fat burning, base endurance |
| Zone 3 | 70-80% | Moderate, breathing harder | Aerobic fitness, cardio |
| Zone 4 | 80-85% | Hard, short sentences only | Anaerobic threshold, speed |
Estimated maximum heart rate by age (Haskell vs Tanaka)
| Age | 220 - age (Haskell) | 208 - 0.7 x age (Tanaka) |
|---|---|---|
| 20 | 200 bpm | 194 bpm |
| 30 | 190 bpm | 187 bpm |
| 40 | 180 bpm | 180 bpm |
| 50 | 170 bpm | 173 bpm |
| 60 | 160 bpm | 166 bpm |
Common mistakes to avoid
- Treating the estimate as your exact max heart rate. Both 220 - age and the Tanaka formula are population averages with a spread of roughly plus or minus 10 to 12 bpm. Your real maximum could be noticeably higher or lower, so use the zones as a guide, not a hard limit, and listen to how the effort feels.
- Guessing your resting heart rate. Karvonen is only as good as the resting pulse you feed it. Measure it first thing in the morning, lying still, before caffeine or activity, ideally averaged over a few days. A figure taken after coffee or movement is too high and shifts every zone.
- Thinking the "fat burn" zone burns the most total fat. The 60 to 70% zone burns a higher proportion of calories from fat, but higher-intensity work burns more total calories (and total fat) per minute. Zone choice should match your goal and recovery, not a belief that low intensity is always best for weight loss.
- Ignoring medication that changes heart rate. Beta-blockers and some other drugs lower both resting and maximum heart rate, so age-based estimates do not apply. If you take such medication, ask your doctor for guidance and consider rating perceived exertion instead.
Glossary
- Maximum heart rate (max HR)
- The highest number of beats per minute your heart reaches during all-out effort. It is estimated from age and declines slowly as you get older.
- Resting heart rate
- Your pulse at complete rest, best measured first thing in the morning. Lower values generally indicate better cardiovascular fitness.
- Heart-rate reserve (HRR)
- The difference between your maximum and resting heart rate. The Karvonen method scales zones within this reserve.
- Karvonen method
- A way to set target zones using heart-rate reserve: target = (max HR - resting HR) x intensity + resting HR. It personalises zones to your fitness.
- Target heart rate zone
- A range of beats per minute that corresponds to a chosen exercise intensity, such as 60 to 70% for steady cardio.
Frequently asked questions
What is a good target heart rate for exercise?
For general fitness, aim for 50 to 70% of your maximum heart rate during moderate exercise and 70 to 85% during vigorous exercise. For a 40-year-old with a max of about 180 bpm, that is roughly 90 to 126 bpm for moderate effort and 126 to 153 bpm for vigorous effort.
How do I calculate my maximum heart rate?
The simplest estimate is 220 minus your age. A formula that fits more recent data is the Tanaka equation, 208 minus 0.7 times your age. Both are averages, so your real maximum may be 10 to 12 bpm higher or lower. A supervised exercise stress test gives the most accurate figure.
What is the Karvonen formula?
The Karvonen formula calculates a target heart rate using your heart-rate reserve: target = (max HR - resting HR) x intensity + resting HR. Because it factors in your resting pulse, it gives zones tailored to your fitness rather than to your age alone.
What heart rate zone burns the most fat?
The 60 to 70% zone burns the highest proportion of calories from fat and is often called the fat-burn zone. However, higher intensities burn more total calories and total fat per minute, so the best zone depends on your goal, time and recovery, not just the fat percentage.
Is 220 minus age accurate?
It is a reasonable average but not precise for any one person, with an error of roughly plus or minus 10 to 12 bpm. It also tends to overestimate the maximum for older adults. The Tanaka formula (208 - 0.7 x age) is often a better fit, and a stress test is best of all.
How do I measure my resting heart rate for the Karvonen method?
Measure it first thing in the morning before getting up, while lying still and relaxed. Count your pulse for a full 60 seconds, or use a fitness tracker, and average it over a few days. Avoid caffeine, alcohol and activity beforehand, since they all raise the reading.
Sources
- Target Heart Rates Chart , American Heart Association
- Exercise intensity: How to measure it , Mayo Clinic