Heart Rate Calculator — Instantly calculate your resting, target, and maximum heart rate! Find your ideal training zones for fitness, fat burning, and cardio health. Mobile-ready, privacy-first, and SEO-optimized for the best experience.
How to Use the Heart Rate Calculator
-
Enter Your Age
Type your age to get an accurate max heart rate and zones.
-
(Optional) Add Resting Heart Rate
For more personalized zones, enter your resting heart rate (e.g., from a morning reading).
-
Choose Gender
For a more accurate max HR formula, select your gender (not required).
-
See Instant Results
Your max HR, target zones, and training ranges update in real time as you type.
-
Copy or Reset
Copy the full results to clipboard for your workout log, or clear all fields to start again.
Why Use a Heart Rate Calculator?
Personalized Fitness
Get accurate heart rate zones for your age and fitness level, not just generic numbers.
Optimal Training
Target the right zone for fat burning, endurance, or peak cardio results.
Safe Workouts
Know your max heart rate and stay within safe limits during intense exercise.
How Does the Heart Rate Calculator Work?
The Heart Rate Calculator uses your age, resting heart rate, and gender to calculate your maximum heart rate (HRmax), target heart rate range, and cardio zones. It uses both standard and advanced formulas for accuracy.
- Max Heart Rate (HRmax): The highest heart rate your body can safely achieve (usually 220 – age, or gender-specific formulas).
- Target Heart Rate: Typically 50–85% of your HRmax, for optimal exercise benefits. [1]
- Heart Rate Reserve (HRR): Uses resting HR for more tailored training zones using the Karvonen formula. [21]
- Training Zones: Fat Burn (50–69%), Cardio (70–84%), Peak (85–100%). [2]
Common Use Cases
Understanding Your Heart Rate Zones in Detail
Training in specific heart rate zones allows you to target different physiological systems for specific outcomes. [2] Using a Heart Rate Calculator is the first step to unlocking this powerful training method. Each zone provides a different stimulus to your body.
Zone 1: Very Light Activity (50-60% of HRmax)
This is your recovery zone. Exercise in this range feels very light and easy. It helps improve blood flow and aids muscle recovery without adding much stress to your body. It is ideal for warm-ups, cool-downs, and active recovery days.
Zone 2: The Fat Burning Zone (60-70% of HRmax)
In this zone, your body primarily uses fat for fuel. [3, 20] Workouts feel comfortable and you can hold a conversation. This zone is excellent for building endurance, improving your body’s ability to utilize fat, and enhancing overall cardiovascular health. Long, slow runs or cycles often target this zone.
Zone 3: The Cardio/Aerobic Zone (70-80% of HRmax)
Training here improves your cardiorespiratory system. You’ll be breathing harder and can only speak in short sentences. This is the sweet spot for improving your VO2 max (your body’s ability to use oxygen) and strengthening your heart muscle, making it more efficient. [2]
Zone 4: The Anaerobic Zone (80-90% of HRmax)
Exercise in this zone is intense and sustainable for only short periods. Your body shifts to using carbohydrates for energy and starts to build up lactic acid. [22] This zone is key for improving your lactate threshold, which means you can sustain high-intensity efforts for longer. It’s often targeted during interval training.
Zone 5: The Peak Zone (90-100% of HRmax)
This is an all-out effort that can only be sustained for very short bursts (a few seconds to a minute). It pushes your muscular and cardiorespiratory systems to their limits. This zone is used by advanced athletes to boost speed and power, often in the final sprint of a race or during high-intensity interval training (HIIT). [23]
The Science Behind the Formulas: Max HR and Karvonen
A Heart Rate Calculator is more than just a simple form; it’s a tool based on decades of exercise physiology research. Understanding the formulas it uses can help you appreciate the results and choose the right method for your needs.
Maximum Heart Rate (HRmax) Formulas
HRmax is a crucial baseline, but it’s an estimate. The most common formulas are:
- Fox Formula (220 – Age): This is the most widely known formula for its simplicity. While it provides a good starting point for the general population, it has a large margin of error and doesn’t account for differences between individuals or genders. [6, 12]
- Tanaka Formula (208 – 0.7 x Age): Research has shown this formula to be more accurate across a wider range of ages and for both men and women, with less variance than the classic “220 – Age” method. [7, 10]
- Gender-Specific Formulas: Our calculator also uses gender-specific formulas (like those by Gellish for men or Gulati for women) when you select a gender. [12, 13] These account for physiological differences, providing a slightly more refined estimate. For instance, women on average tend to have a slightly higher maximum heart rate than men of the same age. [8]
The most accurate way to determine your true HRmax is a medically supervised maximal stress test. However, using a reliable formula from a heart rate calculator is a safe and effective alternative for most people. [5]
The Karvonen Formula (Heart Rate Reserve)
If you enter your Resting Heart Rate (RHR), the calculator can use the Karvonen formula, which is considered a gold standard for personalizing training zones. [15, 21] It works by calculating your Heart Rate Reserve (HRR).
HRR = HRmax – RHR
Your HRR is the actual working range of your heart. A person with a lower RHR is generally more fit and has a larger heart rate reserve. The Karvonen formula then calculates your target zones as a percentage of this reserve, added back to your resting rate:
Target HR = (HRR × %Intensity) + RHR
This method is more accurate because it anchors the calculation to your current fitness level (indicated by your RHR), not just your age. [21] As you get fitter and your RHR drops, your Karvonen-based zones will automatically adjust, making it a dynamic and powerful tool for tracking progress.
How to Accurately Measure Your Resting Heart Rate (RHR)
Your RHR is a powerful indicator of your cardiovascular health and fitness level. For the most precise results from our Heart Rate Calculator, it’s essential to measure it correctly. A lower RHR typically signifies a more efficient heart. [4, 9]
-
Choose the Right Time
The best time to measure RHR is in the morning, right after you wake up, but before you get out of bed, talk, or drink caffeine. [4, 9] Your body is in its most rested state at this point.
-
Find Your Pulse
Use the tips of your first two fingers (not your thumb, as it has its own pulse). Gently press on one of two main locations: the radial artery (on the inside of your wrist, on the thumb side) or the carotid artery (on your neck, to the side of your windpipe). [9]
-
Count the Beats
Set a timer and count the number of beats you feel in 30 seconds. Multiply this number by two to get your beats per minute (bpm). [4] For even greater accuracy, count for a full 60 seconds. [9]
-
Repeat for Consistency
Measure your RHR for 3-5 consecutive mornings and take the average. [4] This will give you a more stable and reliable number, as a single night’s sleep or stress can cause daily fluctuations.
-
Use Technology (Optional)
Many modern smartwatches and fitness trackers automatically measure RHR, especially during sleep. These can be very convenient, but their accuracy can vary. For best results, compare your device’s reading with a manual check.
Glossary of Important Heart Rate Terms
Familiarizing yourself with key terminology will help you get the most out of our Heart Rate Calculator and your fitness journey.
Frequently Asked Questions
We use the standard 220 – age formula by default. If you select a gender, we use more modern formulas like the Tanaka (208 – 0.7 x Age) or other gender-specific equations for greater accuracy. [6, 7]
Entering your resting HR allows the calculator to use the Karvonen formula. This method calculates your Heart Rate Reserve (HRR) to create training zones tailored to your personal fitness level, which is more accurate than age-based estimates alone. [15]
Zones are ranges based on a percentage of your max heart rate. Each zone corresponds to a different exercise intensity and provides different benefits, such as Fat Burn (Zone 2, 60–70%), Cardio/Aerobic (Zone 3, 70–80%), and Peak/Anaerobic (Zones 4-5, 80–100%). [2]
Yes, it’s perfect for High-Intensity Interval Training (HIIT). Use the calculator to find your peak zone (Zone 5) for your high-intensity intervals and your recovery zone (Zone 1) for your rest periods to structure an effective workout.
100% private. All calculations are performed instantly within your browser. No personal data like your age or heart rate is ever sent to or stored on a server.
Yes! The calculator is fully responsive, mobile-friendly, and designed to work quickly and flawlessly on all devices, including phones, tablets, and desktops.
No problem. Simply leave the field blank. The heart rate calculator will use standard formulas based on just your age and gender to compute your target zones.
For best results, measure your pulse just after waking up and before getting out of bed. Use your fingertips to find your pulse on your wrist or neck, count the beats for 30 seconds, and multiply by two. [4, 9]
Yes! This tool is 100% free, with no sign-up requirements, no advertisements, and no limitations on its features.
The calculations are based on established and widely-used formulas from exercise physiology. They provide a very good estimate for most individuals. However, they are for informational and fitness purposes only and should not be considered medical advice. For health concerns, always consult a qualified healthcare provider. [5]