Target Heart Rate Calculator
Calculate your target heart rate zones for different training intensities using the Karvonen method. Enter your age and resting heart rate to get personalized zones.
Calculate your target heart rate zones for different exercise intensities. Choose how to determine your max heart rate, enter your resting heart rate for personalized results, then select an intensity method.
What is Heart Rate
Heart rate is a measure of the number of contractions the heart makes per minute, measured in beats per minute (bpm). To use this calculator effectively, it is important to understand resting heart rate, maximum heart rate, and heart rate reserve.
Maximum Heart Rate
Maximum heart rate (MHR) is the highest number of beats per minute the heart reaches during intense exercise. It is most accurately measured through a cardiac stress test. More commonly, it is estimated using formulas based primarily on age.
It is worth noting that MHR formulas output generalized population averages and can differ significantly from an individual's actual maximum. Dr. Fritz Hagerman observed that Olympic rowers in their 20s had maximum heart rates ranging from 160 to 220 bpm. The theoretical maximum human heart rate is 300 bpm. The three formulas used in this calculator are:
Haskell & Fox Formula (1971)
MHR = 220 − age
The most widely used formula due to its simplicity.
Tanaka, Monahan & Seals Formula (2001)
MHR = 208 − 0.7 × age
Nes, Janszky, Wisloff, Stoylen & Karlsen Formula (2013)
MHR = 211 − 0.64 × age
Resting Heart Rate
Resting heart rate (RHR) is your heart rate when awake and at rest in a neutral environment. A typical RHR for an adult ranges between 50–90 bpm. Very fit athletes often have RHRs in the 40–60 range or below.
| Resting Heart Rate | Classification |
|---|---|
| < 40 bpm | Bradycardia (consult a physician) |
| 40–50 bpm | Athletic / Excellent |
| 50–60 bpm | Good (may be bradycardia in non-athletes) |
| 60–70 bpm | Average |
| 70–80 bpm | Below average |
| 80–90 bpm | Poor |
| > 90 bpm | Tachycardia (consult a physician) |
Heart Rate Reserve
Heart rate reserve (HRR) is the difference between your maximum heart rate and your resting heart rate:
HRreserve = MHR − RHR
For example, a person with MHR of 180 bpm and RHR of 68 bpm has a heart rate reserve of 180 − 68 = 112 bpm. A higher heart rate reserve generally indicates better cardiovascular fitness.
Target Heart Rate Zones
Maintaining a heart rate within a target zone has been found to be beneficial for exercise. A person's target heart rate zone is broken into five zones:
| Zone | Name | % MHR |
|---|---|---|
Zone 1 | Moderate Activity | 50–60% |
Zone 2 | Weight Control | 60–70% |
Zone 3 | Aerobic | 70–80% |
Zone 4 | Anaerobic | 80–90% |
Zone 5 | VO₂ Max | 90–100% |
Exercise Zones by Age
Approximate heart rate ranges by age for each zone using the Haskell & Fox formula (MHR% method):
| Zone / Age | 20 | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 | 65 | 70 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 90–100% | 180–200 | 176–195 | 171–190 | 167–185 | 162–180 | 158–175 | 153–170 | 149–165 | 144–160 | 140–155 | 135–150 |
| 80–90% | 160–180 | 156–176 | 152–171 | 148–167 | 144–162 | 140–158 | 136–153 | 132–149 | 128–144 | 124–140 | 120–135 |
| 70–80% | 140–160 | 137–156 | 133–152 | 130–148 | 126–144 | 123–140 | 119–136 | 116–132 | 112–128 | 109–124 | 105–120 |
| 60–70% | 120–140 | 117–137 | 114–133 | 111–130 | 108–126 | 105–123 | 102–119 | 99–116 | 96–112 | 93–109 | 90–105 |
| 50–60% | 100–120 | 98–117 | 95–114 | 93–111 | 90–108 | 88–105 | 85–102 | 83–99 | 80–96 | 78–93 | 75–90 |
Haskell & Fox Method
The simplest method — target zones are found by multiplying MHR by the desired percentages. Example for a 36-year-old (MHR = 184 bpm) finding the 70–80% zone:
MHR = 220 − 36 = 184 bpm
HR70% = 184 × 0.70 = 129 bpm
HR80% = 184 × 0.80 = 147 bpm
Target zone: 129–147 bpm
Karvonen Method
The Karvonen method uses heart rate reserve (MHR − RHR), making zones more personalized. It is the default when a resting heart rate is entered.
THR = RHR + (MHR − RHR) × intensity%
Same 36-year-old with RHR of 70 bpm, 70–80% zone:
HRreserve = 184 − 70 = 114 bpm
HR70% = 0.70 × 114 + 70 = 150 bpm
HR80% = 0.80 × 114 + 70 = 161 bpm
Target zone: 150–161 bpm
Rating of Perceived Exertion (RPE)
RPE is a subjective measure of exercise intensity that does not require physiological measurement. Studies show individuals can accurately estimate exertion levels like "moderate" and "intense." There are two commonly used scales.
Borg Scale (6–20)
Ranges from 6 (no exertion) to 20 (maximum exertion). Each value multiplied by 10 approximates heart rate at that level.
| RPE | Intensity | Approx. HR |
|---|---|---|
| 6 | No exertion at all | 60 |
| 7 | Extremely light | 70 |
| 9 | Very light | 90 |
| 11 | Light | 110 |
| 12 | Moderate | 120 |
| 13 | Somewhat hard | 130 |
| 15 | Hard | 150 |
| 17 | Very hard | 170 |
| 19 | Extremely hard | 190 |
| 20 | Maximal exertion | 200 |
THR = RHR + (MHR − RHR) × (B − 6) / 14
where B = Borg scale value (6–20)
Example: "Somewhat hard" (B = 13), MHR = 190, RHR = 60:
THR = 60 + (190 − 60) × (13 − 6) / 14 = 125 bpm
Borg CR10 Scale (0–10)
The modified Borg scale uses a 0–10 range. 0 = no exertion; 10 = strongest exertion experienced.
| RPE | Intensity |
|---|---|
| 0 | No exertion |
| 0.5 | Noticeable |
| 1 | Very light |
| 2 | Light |
| 3 | Moderate |
| 4 | Somewhat difficult |
| 5 | Difficult |
| 7 | Very difficult |
| 9 | Almost maximal |
| 10 | Maximal |
THR = RHR + (MHR − RHR) × B / 10
where B = Borg CR10 value (0–10)
Example: "Somewhat difficult" (B = 4), MHR = 190, RHR = 60:
THR = 60 + (190 − 60) × 4 / 10 = 112 bpm