Calculate your target heart rate based on your age and your desired training effort. Training effort is commonly expressed as a percentage of your maximum heart rate (or, with the Karvonen method, as a percentage of your heart rate reserve). Not sure what heart rate you want to be at? Check out the table below for your target heart rate.

Heart Rate Zone Calculator

Zone 1 (50–60 %) – —
Zone 2 (60–70 %) – —
Zone 3 (70–80 %) – —
Zone 4 (80–90 %) – —
Zone 5 (90–100 %) – —

Safety note: This calculator provides general fitness estimates and is not medical advice. Do not use these targets to guide vigorous or near-max exercise if you have heart disease, chest pain, unexplained shortness of breath, fainting, uncontrolled high blood pressure, are pregnant, or take medications that affect heart rate (for example, beta blockers) unless you have been cleared by a clinician. Stop exercising and seek care if you develop chest pain, severe shortness of breath, dizziness, or fainting. Heart rate can lag behind effort at high intensity; many people find perceived exertion or the “talk test” safer than strict heart-rate targets.

Heart Rate Zone Formula

The following formulas are used to (1) calculate a target heart rate from a chosen effort percentage and (2) determine what percentage of your max heart rate you are currently at.

Target HR = Effort × MHR
Effort (%) = (HR / MHR) × 100
Karvonen Target HR = HRrest + Effort × (MHR − HRrest)

To calculate a target heart rate for a zone, estimate your maximum heart rate (MHR), then multiply MHR by the zone percentage (for example, 0.70 for 70%). If you use the Karvonen method, calculate heart rate reserve (MHR − resting HR) and add resting HR back in after applying the percentage.

  1. Easy / recovery (Zone 1): 50–60% of maximum heart rate
  2. Easy endurance (Zone 2): 60–70% of maximum heart rate
  3. Moderate aerobic (Zone 3): 70–80% of maximum heart rate
  4. Hard / threshold (Zone 4): 80–90% of maximum heart rate
  5. Very hard / near-max (Zone 5): 90–100% of maximum heart rate

Zone boundaries and labels vary by system and device (for example, some guidance uses %HRmax, others use %HRR or ventilatory/lactate thresholds). For general intensity guidance, compare with reputable exercise-prescription resources such as ACSM recommendations. If your goal is fat loss, overall energy balance (calories in vs. calories out) matters most; zones can help plan intensity but do not guarantee fat loss on their own.

What is a heart rate zone?

You might be asking, what is a heart rate zone? Simply speaking, a heart rate zone is a range of heart rate, in beats per minute, that is determined by a percentage of your maximum heart rate (or by a percentage of heart rate reserve when using the Karvonen method). What these heart rate zones mean in terms of exercise is described in the picture below.

heart rate zones

As you can see in the chart above, there are 5 common categories for training by heart rate.

  1. Easy / recovery (Zone 1): 50–60% of maximum heart rate
  2. Easy endurance (Zone 2): 60–70% of maximum heart rate
  3. Moderate aerobic (Zone 3): 70–80% of maximum heart rate
  4. Hard / threshold (Zone 4): 80–90% of maximum heart rate
  5. Very hard / near-max (Zone 5): 90–100% of maximum heart rate

Remember that these zones are guidelines. Age-based maximum heart rate formulas are estimates and often have typical prediction errors on the order of about 10–12 bpm (or more) for individuals. At very high intensity (Zone 5), heart rate can also lag behind effort and varies day-to-day, so zone boundaries can be less reliable than at moderate intensities. To learn more about aerobic fitness (VO2max), click here.

Maximum Heart Rate formula

Since these zone values are based on an estimated maximum heart rate (MHR), you may wonder how to calculate MHR. Many formulas use age, but different researchers have proposed different equations. Here are five commonly used formulas:

  • Fox (Haskell & Fox): MHR = 220 − age
  • Gellish2: MHR = 191.5 − 0.007 × age2
  • Fairburn: MHR = 201 − 0.63 × age (women)
    OR MHR = 208 − 0.80 × age (men)
  • Gellish: MHR = 206.9 − 0.67 × age
  • Tanaka: MHR = 208 − 0.7 × age

In the calculator above, you can choose between Tanaka or Fox for estimating MHR. If you choose Karvonen (heart rate reserve), the calculator uses Tanaka to estimate MHR and then computes target zones from heart rate reserve. No single formula is “best” for everyone, and any age-based formula can be off by a meaningful amount for an individual, so treat the results as a starting point rather than a medical or performance diagnosis.

So, what zone should you train in? That depends on your goals. Many people do a lot of steady cardio work in lower-to-moderate zones (often Zones 2–3). High-intensity interval training (HIIT) alternates harder efforts with easier recovery and can improve conditioning in less time, but it is more stressful. If your goal is fat loss, the biggest driver is overall energy balance (calories in vs. calories out); heart-rate zones can help you plan training intensity, but there is no single “most fat-burning” zone that guarantees fat loss.

Calculator Change Log:

  • 6/12/25 – Added a formula drop down selector and clearer outputs for zones in percentage and beats per minute.