How to Calculate Heart Rate Formula

Target Heart Rate Calculator

Measure while at rest for 60 seconds.

70%

Calculation Results:

Max Heart Rate

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BPM

Target Heart Rate

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BPM

function calculateHeartRate() { var age = document.getElementById('hr_age').value; var rhr = document.getElementById('hr_rhr').value; var intensityPercent = document.getElementById('hr_intensity').value; var intensity = intensityPercent / 100; if (!age || age 120) { alert("Please enter a valid age."); return; } if (!rhr || rhr 250) { alert("Please enter a valid resting heart rate."); return; } // Fox Formula for Maximum Heart Rate var mhr = 220 – age; // Karvonen Formula for Target Heart Rate (Target Heart Rate = ((Max HR − Resting HR) × %Intensity) + Resting HR) var heartRateReserve = mhr – rhr; var thr = (heartRateReserve * intensity) + parseFloat(rhr); document.getElementById('res_mhr').innerHTML = Math.round(mhr); document.getElementById('res_thr').innerHTML = Math.round(thr); var zoneText = ""; if (intensityPercent < 60) { zoneText = "Recovery Zone: Good for warming up and active recovery."; } else if (intensityPercent < 70) { zoneText = "Fat Burning Zone: Ideal for weight loss and building basic endurance."; } else if (intensityPercent < 80) { zoneText = "Aerobic Zone: Improves cardiovascular fitness and lung capacity."; } else if (intensityPercent < 90) { zoneText = "Anaerobic Zone: Increases lactic acid tolerance and high-speed performance."; } else { zoneText = "Red Line Zone: Maximum effort, used for short interval training."; } document.getElementById('zone_info').innerHTML = "Training Context: " + zoneText; document.getElementById('hr_results_area').style.display = 'block'; }

Understanding the Heart Rate Formula

Knowing how to calculate your heart rate is essential for optimizing your cardiovascular health and ensuring your workouts are effective. Whether you are training for a marathon or just trying to lose weight, staying within a specific target heart rate zone helps you reach your goals safely.

1. Maximum Heart Rate (MHR)

The most common method to calculate your maximum heart rate is the Fox Formula. It provides an estimate of the highest number of times your heart can safely beat in one minute during maximum effort.

Formula: 220 – Age = Max HR

Example: If you are 40 years old, your estimated Max HR is 180 beats per minute (BPM).

2. The Karvonen Formula

While the Fox formula is simple, the Karvonen formula is more accurate because it accounts for your Resting Heart Rate (RHR). This measures your Heart Rate Reserve (HRR) to give a more personalized target.

Formula: ((Max HR – Resting HR) × % Intensity) + Resting HR = Target HR

Target Heart Rate Zones

Different intensity levels result in different physiological benefits:

• Moderate Intensity (50% – 70%): Great for beginners and long-duration fat-burning sessions.
• Vigorous Intensity (70% – 85%): Improves aerobic capacity and overall cardiovascular strength.
• Maximum Effort (85% – 100%): High-intensity intervals (HIIT) to improve peak performance.

A Realistic Example

Let's calculate the target heart rate for a 30-year-old with a resting heart rate of 60 BPM who wants to exercise at 70% intensity:

1. Calculate Max HR: 220 – 30 = 190 BPM
2. Calculate Heart Rate Reserve: 190 – 60 = 130 BPM
3. Calculate Target: (130 × 0.70) + 60 = 151 BPM

This individual should aim for approximately 151 BPM during their workout to stay in the aerobic training zone.

How to Measure Your Resting Heart Rate

For the most accurate calculation, find your resting heart rate first thing in the morning before you get out of bed. Place two fingers on your wrist (radial pulse) or neck (carotid pulse), count the beats for 60 seconds, and use that number in the calculator above.