Target Heart Rate Calculator

Target Heart Rate Calculator

Target Heart Rate Calculator

What is Heart Rate?

Heart rate refers to how many times the heart beats in one minute, measured in beats per minute (bpm). To properly use a target heart rate calculator, it’s important to understand three key terms: resting heart rate, maximum heart rate, and heart rate reserve

Maximum Heart Rate (MHR)

The maximum heart rate is the highest number of beats your heart can safely reach during very intense exercise. The most precise way to measure it is through a cardiac stress test, where you exercise (often on a treadmill) while your heart activity is monitored by an ECG. The intensity increases until your body shows signs of maximum exertion. While the theoretical upper limit is around 300 bpm, actual values vary widely.

Because stress testing isn’t always practical, formulas are often used to estimate MHR. These formulas are based mainly on age and provide averages, but they don’t always reflect individual differences. For example, research has shown that even Olympic athletes of the same age can have maximum heart rates ranging from 160 to 220 bpm, proving how much variation there can be.

Common formulas for estimating MHR include:
  • Haskell & Fox (1971): MHR = 220 – age
  • T
    anaka, Monahan & Seals (2001):     MHR = 208 – (0.7 × age)
  • Nes et al. (2013): MHR = 211 – (0.64 × age)

Resting Heart Rate (RHR)

Your resting heart rate is the number of beats per minute when you’re awake, relaxed, and not under stress. You can measure it by checking your pulse for 60 seconds or by using a heart rate monitor.

For most adults, a normal RHR falls between 50–90 bpm. Older sources suggest 60–100 bpm, but current research leans toward the lower range. Athletes often have RHRs below 60 bpm, which is considered normal for highly trained individuals. A consistently high RHR (above 90–100 bpm) may indicate tachycardia, while a very low RHR (below 50 bpm in non-athletes) may be considered bradycardia.

Heart Rate Reserve (HRR)

Heart rate reserve is the difference between your maximum and resting heart rates:
HRR=MHR–RHR
HRR = MHR – RHR
HRR=MHR–RHR

For example, if your maximum heart rate is 180 bpm and your resting rate is 68 bpm:
HRR=180–68=112
HRR = 180 – 68 = 112
HRR=180–68=112

This number is useful for calculating training zones with the Karvonen method (explained later).

Target Heart Rate Zones

Training at different percentages of your heart rate helps target specific fitness goals. Staying too far below your target zone won’t challenge your body enough, while going too high may cause fatigue or injury.

The five common zones are:
  1. Zone 1 (50–60%) – Light activity such as warming up, cooling down, or recovery days.
  2. Z
    one 2 (60–70%)     – Improves endurance and fat metabolism. A pace you can maintain for a long time.
  3. Zone 3 (70–80%) – Builds strength and aerobic capacity. Effort feels moderate to hard.
  4. Zone 4 (80–90%) – High-intensity training close to your limit. Improves speed and performance.
  5. Z
    one 5 (90–100%)     – Maximum effort, only sustainable for short bursts. Useful for peak conditioning but requires longer recovery.

Methods for Measuring Exercise Intensity

1. Haskell & Fox Method
This popular but basic method uses only age to estimate MHR:
MHR=220–age
MHR = 220 – age
MHR=220–age

Example: For a 36-year-old, MHR = 184 bpm. To find the 70–80% training zone:
  • 184 × 0.70 = 129 bpm
  • 184 × 0.80 = 147 bpm
So, their target range is 129–147 bpm for moderate exercise.
Other formulas (Tanaka or Nes) can also be applied the same way.

Karvonen Method (HRR Method)
This method is more personalized since it factors in your resting heart rate.

Formula: THR = RHR + (HRR × Intensity%)

Example: A 36-year-old with RHR = 70 bpm and MHR = 184 bpm. HRR=184–70=114HRR = 184 – 70 = 114HRR=184–70=114

For 70–80% training zone:
  • 0.70 × 114 + 70 = 150 bpm
  • 0.80 × 114 + 70 = 161 bpm
So, the target range is 150–161 bpm.
Rating of Perceived Exertion (RPE)
Instead of relying on heart rate, RPE lets you rate how hard you feel you’re working. Research shows people can judge intensity fairly accurately without equipment. There are two common RPE scales:
  • Borg Scale (6–20): Each value × 10 roughly matches heart rate. For example, RPE 13 (“somewhat hard”) corresponds to about 130 bpm.
  • Borg CR10 Scale (0–10): A simpler version, where 0 = no effort and 10 = maximum effort.
n style="font-weight: 400;">Formulas can also connect RPE with heart rate, but the key idea is learning to listen to your body’s signals.

In summary:

  • Heart rate measures your heart’s beats per minute.
  • MHR shows your maximum potential, RHR reflects your baseline, and HRR gives you a personalized range for training.
  • Training zones (1–5) guide whether you’re working on endurance, strength, or peak performance.
  • Methods like Haskell & Fox, Karvonen, and RPE help you calculate and monitor your effort.