Heart Rate Calculator
Find your target heart rate zones
Your Heart Rate Zones
Zone 1: Very Light
Improves basic endurance and fat burning. Perfect for recovery days.
Zone 2: Light
Optimal fat burning zone. Builds general endurance efficiently.
Zone 3: Moderate
Improves aerobic capacity and cardiovascular fitness.
Zone 4: Hard
Builds speed endurance and improves performance.
Zone 5: Maximum
Develops maximum performance and peak power.
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Evidence-Based Information
Based on scientific research and guidelines from leading health organizations
Target Heart Rate Calculator: The Scientific Way to Optimize Your Workout
Reaching your fitness goals requires more than just hard work; it requires smart work. Whether your aim is to burn fat, build endurance, or elevate your cardiovascular health to its peak, the key is hidden in your "heart rate."
So, how hard should you push during a workout? If you go too slowly, you won't get the results you want. If you go too hard, you risk injury or "burnout."
This is where your Target Heart Rate (THR) comes in. Your target heart rate zone is the "sweet spot" that indicates the most efficient and safe exercise intensity for your specific fitness goals.
Use our Target Heart Rate Calculator above to discover your personalized zones in seconds, and then keep reading to learn the science behind the numbers.
Heart Rate & Exercise: The Core Concepts You Need to Know
To fully understand the results from our calculator, you first need to be familiar with three fundamental metrics:
1. Resting Heart Rate (RHR)
Your Resting Heart Rate is the number of times your heart beats per minute (bpm) when you are in a state of complete rest (for example, just after you wake up in the morning).
Why It Matters: A lower RHR is often an indicator of a more efficient heart function and better cardiovascular fitness.
How to Measure: For the most accurate reading, measure your pulse (at the wrist or neck) for 60 seconds immediately upon waking, before getting out of bed.
What's Normal? For most healthy adults, a typical RHR is between 60 and 100 bpm. For well-conditioned athletes, this number can often be as low as 40-50 bpm.
2. Maximum Heart Rate (MHR)
Your Maximum Heart Rate is the theoretical highest number of beats per minute your heart can reach during intense, all-out exercise. This is your personal "red line."
Why It Matters: All of your target heart rate zones are calculated as a percentage of this maximum value.
How to Measure: The most accurate method is a clinical cardiac stress test in a lab. However, this isn't practical for most people. Therefore, we use age-based formulas to estimate it.
The Most Popular Maximum Heart Rate (MHR) Formulas
| Formula Name | Calculation Method | Who Is It Generally For? |
|---|---|---|
| Haskell & Fox (1971) | 220 - Age | The most well-known and simplest formula. A good starting point for the general population. |
| Tanaka, Monahan & Seals (2001) | 208 - (0.7 × Age) | Considered more accurate for the age-related decline in MHR. Often more precise for adults over 40. |
| Nes, Janszky, Wisloff (2013) | 211 - (0.64 × Age) | A newer study. May provide a better estimate, especially for fitter individuals who exercise regularly. |
Important Note: All of these formulas are estimates. Listening to your own body should always be your most important guide.
3. Heart Rate Reserve (HRR)
Your Heart Rate Reserve is the difference between your Maximum Heart Rate (MHR) and your Resting Heart Rate (RHR). This represents your "usable" or "working" heart rate range.
Formula: Heart Rate Reserve (HRR) = Maximum Heart Rate (MHR) - Resting Heart Rate (RHR)
Why It Matters? The HRR is the foundation of the Karvonen Method, a more personalized and advanced way to calculate your exercise intensity zones.
What Are Target Heart Rate Zones and What Does Each Zone Do?
Now that we know the basic metrics, we get to the exciting part: The Zones. Target heart rate zones are intensity levels based on percentages of your MHR. Each zone provides a different benefit to your body.
The 5 Exercise Intensity Zones
| Zone | Intensity (% of MHR) | What Happens Here? (Primary Benefit) | How It Feels ("Talk Test") |
|---|---|---|---|
| Zone 1: Very Light | 50% - 60% | Active Recovery / Warm-up: Prepares the body for exercise, increases blood flow. Ideal for cool-downs. | Very comfortable. You can easily carry on a full conversation. |
| Zone 2: Light | 60% - 70% | Fat Burn / Endurance: Known as the "aerobic zone." This is where the body primarily uses fat for fuel. Perfect for long, steady endurance training. | Comfortable. You can still speak in full sentences without much effort. |
| Zone 3: Moderate | 70% - 80% | Aerobic Fitness / Cardio Improvement: Strengthens your cardiovascular system. This zone improves lung capacity and heart efficiency. | Controlled effort. You can only speak in short sentences. |
| Zone 4: Hard | 80% - 90% | Anaerobic Threshold: The point where your body begins to produce lactic acid. Builds speed, power, and performance. HIIT workouts target this zone. | Very hard. You can only manage a few words at a time. |
| Zone 5: Maximum | 90% - 100% | Maximal Effort / Speed: Your all-out sprint. This can only be sustained for very short bursts (e.g., 30-60 seconds). Builds peak muscle power and speed. | All-out. Talking is impossible. |
How Your Target Heart Rate Zones Are Calculated: Two Key Methods
While our calculator does the math for you, it's important to understand how it works.
Method 1: The Standard (Haskell & Fox) Method
This is the simplest method and is based only on your Maximum Heart Rate (MHR).
Formula: Target Heart Rate = MHR × % Intensity
Example (for a 40-year-old):
MHR (Estimated) = 220 - 40 = 180 bpm
Fat Burn Zone (60%-70%) = 180 × 0.60 = 108 bpm to 180 × 0.70 = 126 bpm.
Method 2: The Karvonen Method (Heart Rate Reserve - HRR Method)
This is a more advanced and more personalized method because it factors in your unique Resting Heart Rate (RHR).
Formula: Target Heart Rate = ((MHR - RHR) × % Intensity) + RHR
Example (Same 40-year-old, but with an RHR of 65 bpm):
MHR = 180 bpm
RHR = 65 bpm
Heart Rate Reserve (HRR) = 180 - 65 = 115 bpm
Fat Burn Zone (60%-70%):
Lower End (60%): (115 × 0.60) + 65 = 69 + 65 = 134 bpm
Upper End (70%): (115 × 0.70) + 65 = 80.5 + 65 = 145.5 bpm
See the difference? For the same person, the standard method gave a range of 108-126 bpm, while the Karvonen method, which accounts for their better fitness (lower RHR), gave a range of 134-145 bpm. This can completely change the intensity of your workout!
What If I Don't Have a Heart Rate Monitor? The RPE Scale
Technology is great, but it isn't always necessary. Your body has an excellent built-in sensor for telling you how hard you're working. This is called the Rate of Perceived Exertion (RPE).
The most common is the Borg 6-20 Scale. This scale was designed to roughly estimate your heart rate.
How it Works: The number on the scale, when multiplied by 10, gives you a rough approximation of your current heart rate. (e.g., If you feel you are at a "13" on the scale, your heart rate is likely around 130 bpm).
Borg RPE Scale vs. Heart Rate Zones
| RPE Scale (6-20) | Perceived Exertion | Correlated Heart Rate Zone |
|---|---|---|
| 6-8 | No exertion at all | Zone 1 (Rest) |
| 9-11 | Very light | Zone 1-2 (Warm-up / Light Cardio) |
| 12-14 | Somewhat hard | Zone 3 (Aerobic / Moderate Cardio) |
| 15-17 | Hard | Zone 4 (Anaerobic Threshold) |
| 18-20 | Very, very hard / Maximal | Zone 5 (Maximal Effort) |
Conclusion: Know Your Zones, Reach Your Goals
Knowing your target heart rate zones gives you a roadmap. It removes the guesswork from your training and makes every session more efficient, safer, and more goal-oriented.
Whether you are just starting out or are a seasoned athlete, use our target heart rate calculator to find your personal zones, plan your workouts accordingly, and start seeing the results.
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Medical Disclaimer
This Heart Rate Calculator is an educational tool designed to provide general information and should not be considered medical advice. The results are based on standard heart rate formulas and may not account for individual health circumstances, medications, or concurrent medical conditions. Heart rate calculations have inherent limitations and should be used as a general guide rather than an absolute prescription. Always consult with a qualified healthcare professional for proper interpretation of your results, personalized exercise recommendations, and treatment plans. Do not make changes to medications or exercise regimens based solely on calculator results without consulting your physician.
Sources and References
The information and calculations on this page are based on established guidelines and research from leading health organizations. We are committed to providing accurate and transparent information.
- American Heart Association - "Target Heart Rates"
- Tanaka, H., Monahan, K. D., & Seals, D. R. (2001) - "Age-predicted maximal heart rate revisited"
- Nes, B. M., Janszky, I., & Wisløff, U. (2013) - "Age-predicted maximal heart rate in healthy subjects"
- American College of Sports Medicine - "Target Heart Rate Chart"
Frequently Asked Questions (FAQ)
Which heart rate formula is most accurate?
The Tanaka formula (208 - 0.7 x Age) is generally more accurate for adults over 40 than the traditional 220-Age formula.
What is the fat burning zone?
Typically Zone 2 (60-70% of Max HR). This intensity uses fat as the primary fuel source while preserving muscle glycogen.
How to find resting heart rate?
Measure your pulse for 60 seconds first thing in the morning before getting out of bed for the most accurate reading.