Target Heart Rate Calculator

Target heart rate calculator for cardio training zones

This Target Heart Rate Calculator helps you estimate a safe, useful heart rate range to aim for during cardio workouts. The intent is simple: you want a target range you can follow on a watch or treadmill display to keep your session at the right effort for your goal. For most people, that goal is steady cardio that builds fitness without turning every workout into an all out effort.

The calculator uses your age to estimate your maximum heart rate, then applies an intensity range to produce a lower and upper target. If you add your resting heart rate, it can estimate your heart rate reserve and calculate a more personalised target range using the Karvonen method. That usually makes the range feel more realistic for people whose resting heart rate is clearly above or below average.

To use it, enter your age, choose an intensity preset, and press Calculate. The result shows your target heart rate range in beats per minute (bpm), plus supporting values like estimated maximum heart rate and the method used. If you want more control, open the Advanced section and enter your resting heart rate and a custom intensity range. You do not need advanced inputs to get a useful answer.

Assumptions and how to use this calculator

• Maximum heart rate is estimated as 220 minus age, which is a common quick estimate and not a medical measurement.
• If resting heart rate is provided, the calculator uses heart rate reserve (max minus resting) and applies the Karvonen method to estimate targets.
• If resting heart rate is not provided, the calculator uses a simple percent of estimated maximum heart rate.
• Intensity presets are designed for steady cardio training, not sprint intervals, racing, or maximal testing.
• Results are guidance for typical healthy adults; if you have heart conditions, are on heart rate affecting medication, or have unusual symptoms, use clinician guidance instead of generic zones.

Common questions

Why are there two methods (simple percent vs Karvonen)?

The simple method uses a percentage of estimated maximum heart rate. It is fast and works when you do not know your resting heart rate. The Karvonen method uses heart rate reserve, which adjusts the targets based on how low your heart rate is at rest, often giving a better fit for people with very low or high resting values.

What should I enter for resting heart rate?

Use a calm, seated or lying measurement taken after a few minutes of rest, ideally in the morning before caffeine or activity. If you only have a rough estimate, leave it blank and use the simple method. A bad resting value can make the Karvonen range worse, not better.

What intensity should I pick for general fitness and fat loss?

For steady sessions where you can talk in short sentences, Moderate (50% to 70%) is usually appropriate. If you are doing harder sustained efforts, Vigorous (70% to 85%) is more demanding. If you are unsure, start with Moderate and adjust based on how the workout feels across multiple sessions.

My heart rate goes above the target range during hills or heat. Is that wrong?

Not necessarily. Heart rate responds to temperature, dehydration, stress, sleep, and terrain. Use the range as a guide, not a strict rule. If you repeatedly overshoot your target at the same pace, it may indicate fatigue, poor recovery, or that the workout intensity is higher than you think.

Does this replace a medical test or a coached training plan?

No. It estimates targets using common formulas and typical intensity bands. It does not measure your true maximum heart rate, lactate threshold, or clinical risk. If you train competitively, have symptoms, or take medication that affects heart rate, you should rely on professional guidance and objective testing where appropriate.