Calculate Hr

Target Heart Rate Calculator

(Measure your pulse for 15 seconds and multiply by 4, or use a fitness tracker)

Your Heart Rate Zones:

function calculateTargetHR() { var age = parseFloat(document.getElementById('userAge').value); var restingHR = parseFloat(document.getElementById('restingHR').value); var errorOutput = document.getElementById('errorOutput'); var mhrOutput = document.getElementById('mhrOutput'); var hrrOutput = document.getElementById('hrrOutput'); var moderateZoneOutput = document.getElementById('moderateZoneOutput'); var vigorousZoneOutput = document.getElementById('vigorousZoneOutput'); errorOutput.innerHTML = "; // Clear previous errors mhrOutput.innerHTML = "; hrrOutput.innerHTML = "; moderateZoneOutput.innerHTML = "; vigorousZoneOutput.innerHTML = "; if (isNaN(age) || age 120) { errorOutput.innerHTML = 'Please enter a valid age (1-120 years).'; return; } if (isNaN(restingHR) || restingHR 100) { errorOutput.innerHTML = 'Please enter a valid resting heart rate (30-100 bpm).'; return; } // Calculate Maximum Heart Rate (MHR) using the common formula: 220 – Age var maxHR = 220 – age; // Calculate Heart Rate Reserve (HRR) var hrr = maxHR – restingHR; if (hrr <= 0) { errorOutput.innerHTML = 'Resting Heart Rate cannot be greater than or equal to Maximum Heart Rate. Please check your inputs.'; return; } // Calculate Target Heart Rate (THR) Zones using the Karvonen Formula: // THR = ((Max HR – Resting HR) * % Intensity) + Resting HR // Moderate Intensity Zone (50% to 70% of HRR) var moderateLower = Math.round((hrr * 0.50) + restingHR); var moderateUpper = Math.round((hrr * 0.70) + restingHR); // Vigorous Intensity Zone (70% to 85% of HRR) var vigorousLower = Math.round((hrr * 0.70) + restingHR); var vigorousUpper = Math.round((hrr * 0.85) + restingHR); mhrOutput.innerHTML = 'Maximum Heart Rate (MHR): ' + maxHR + ' bpm'; hrrOutput.innerHTML = 'Heart Rate Reserve (HRR): ' + hrr + ' bpm'; moderateZoneOutput.innerHTML = 'Moderate Intensity Zone (50-70%): ' + moderateLower + ' – ' + moderateUpper + ' bpm'; vigorousZoneOutput.innerHTML = 'Vigorous Intensity Zone (70-85%): ' + vigorousLower + ' – ' + vigorousUpper + ' bpm'; } // Run calculation on page load with default values window.onload = calculateTargetHR;

Understanding Your Target Heart Rate (THR)

Your heart rate is a vital sign that indicates how many times your heart beats per minute (bpm). It's a crucial metric for understanding your cardiovascular health and optimizing your exercise routine. Knowing your target heart rate zones can help you train effectively, whether your goal is to improve endurance, burn fat, or enhance overall fitness.

What is Heart Rate?

Simply put, your heart rate is the number of times your heart contracts in one minute. It fluctuates based on your activity level, emotions, body temperature, and even medications. A healthy resting heart rate for adults typically ranges from 60 to 100 bpm, though well-trained athletes often have lower resting rates.

Key Heart Rate Metrics Explained:

  • Resting Heart Rate (RHR): This is your heart rate when you are at rest, ideally measured first thing in the morning before you get out of bed. A lower RHR generally indicates better cardiovascular fitness.
  • Maximum Heart Rate (MHR): This is the highest rate your heart can achieve during intense physical activity. A common estimation formula is 220 minus your age. While this is a good general guideline, individual maximum heart rates can vary.
  • Heart Rate Reserve (HRR): This is the difference between your Maximum Heart Rate and your Resting Heart Rate (MHR – RHR). HRR represents the range of heartbeats available for exercise.
  • Target Heart Rate (THR) Zones: These are specific heart rate ranges that correspond to different exercise intensities. Training within these zones helps you achieve specific fitness goals. The Karvonen Formula, which uses your HRR, is often considered more accurate for determining these zones than simply using a percentage of MHR.

How to Measure Your Resting Heart Rate:

To get an accurate RHR, sit quietly for a few minutes. Place your index and middle fingers on your neck to the side of your windpipe (carotid artery) or on your wrist (radial artery). Count the number of beats in 15 seconds and multiply by four to get your beats per minute. For best results, do this several mornings in a row and average the readings.

Understanding Your Target Heart Rate Zones:

Our calculator uses the Karvonen Formula to provide two key training zones:

  • Moderate Intensity Zone (50-70% of HRR): This zone is ideal for improving general cardiovascular health, burning fat, and building endurance. You should be able to hold a conversation comfortably in this zone.
  • Vigorous Intensity Zone (70-85% of HRR): This zone pushes your cardiovascular system harder, leading to greater improvements in aerobic fitness and calorie expenditure. You'll likely be breathing heavily and find it difficult to speak more than a few words.

Why is Training in Your THR Zone Important?

Exercising within your target heart rate zones ensures you're working out at an intensity that is effective for your goals without overtraining or undertraining. It helps you:

  • Optimize calorie burning.
  • Improve cardiovascular endurance.
  • Enhance athletic performance.
  • Monitor your progress over time.

Example Calculation:

Let's say you are 30 years old with a Resting Heart Rate of 65 bpm:

  • Maximum Heart Rate (MHR): 220 – 30 = 190 bpm
  • Heart Rate Reserve (HRR): 190 bpm (MHR) – 65 bpm (RHR) = 125 bpm
  • Moderate Intensity Zone (50-70%):
    • Lower end (50%): (125 * 0.50) + 65 = 62.5 + 65 = 127.5 bpm (approx. 128 bpm)
    • Upper end (70%): (125 * 0.70) + 65 = 87.5 + 65 = 152.5 bpm (approx. 153 bpm)
    • Your Moderate Zone: 128 – 153 bpm
  • Vigorous Intensity Zone (70-85%):
    • Lower end (70%): (125 * 0.70) + 65 = 87.5 + 65 = 152.5 bpm (approx. 153 bpm)
    • Upper end (85%): (125 * 0.85) + 65 = 106.25 + 65 = 171.25 bpm (approx. 171 bpm)
    • Your Vigorous Zone: 153 – 171 bpm

This means for a 30-year-old with an RHR of 65, a moderate workout would aim for a heart rate between 128-153 bpm, while a vigorous workout would target 153-171 bpm.

Important Disclaimer:

This calculator provides general estimates based on common formulas. Individual heart rates can vary due to genetics, fitness level, and health conditions. Always consult with a healthcare professional or a certified fitness expert before starting any new exercise program, especially if you have underlying health issues or are taking medications that affect heart rate.

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