Heart Rate Zone Calculator

Heart Rate Zone Calculator – Find Your 5 Training Zones

This Heart Rate Zone Calculator helps you turn abstract pulse numbers into clear training zones. By combining your age, optional resting heart rate and well-known formulas, it estimates your maximum heart rate and then splits it into five training zones from very easy recovery to very hard intervals.

You can use these zones for running, cycling, rowing, gym cardio sessions and even brisk walking. The calculator outputs numeric ranges, while the article below explains the formulas behind the scenes so you understand what each number means.

Key Formulas Used In This Heart Rate Zone Calculator

The calculator uses two main ingredients: an estimate of your maximum heart rate and a set of percentage ranges that define the zones. In the Karvonen mode, it also uses your resting heart rate to personalize those zones.

1. Age-Based Maximum Heart Rate Formulas

The simplest way to estimate maximum heart rate is to subtract your age from a constant. Two common formulas are used in practice:

The classic 220 − age formula is easy to remember but can overestimate or underestimate some people. The Tanaka formula 208 − 0.7 × age is based on a large study and often gives slightly lower values, especially for older athletes. The calculator lets you switch between these formulas in the tabs.

2. Percentage-Based Heart Rate Zones

Once an estimated maximum heart rate is known, simple zones are defined as percentages of that max. A common five-zone system looks like this:

• Zone 1: 50% to 60% of max HR
• Zone 2: 60% to 70% of max HR
• Zone 3: 70% to 80% of max HR
• Zone 4: 80% to 90% of max HR
• Zone 5: 90% to 100% of max HR

For example, if your maximum heart rate estimate is 190 bpm, then Zone 2 (60% to 70%) is:

The calculator applies these percentages automatically and rounds results according to your decimal setting so you can read and remember them easily.

3. Karvonen Formula (Heart Rate Reserve)

The Karvonen method uses heart rate reserve, which is the difference between your maximum and resting heart rate. This can better reflect how hard your heart is working relative to your personal range.

If your max HR is 190 and your resting HR is 60, then your heart rate reserve is 130 bpm. A 70% effort using Karvonen would be:

The Karvonen tab builds full zone ranges by applying a low and high intensity to this formula, for example 0.6 and 0.7 for Zone 2 or 0.8 and 0.9 for Zone 4.

How The Calculator Uses These Formulas In Each Tab

Tab 1: By Age (Simple Zones)

In the By Age tab, you enter your age and choose the maximum heart rate formula. The calculator first estimates max HR using either:

It then creates five zones using percentage bands of that max. The table shows for each zone the intensity description, percentage range and heart rate range in beats per minute. This is the quickest way to get approximate zones if you do not know your resting heart rate.

Tab 2: Karvonen Zones (With Resting HR)

In the Karvonen tab, the calculator still estimates max HR from your age, but it also uses your resting heart rate. The steps are:

1. Estimate max HR from age (220 − age or 208 − 0.7 × age).
2. Compute heart rate reserve: HRR = Max HR − Resting HR.
3. Build zones using Target HR = Resting HR + HRR × intensity.

For example, a Karvonen Zone 3 might use 70% to 80% of heart rate reserve:

This method can distinguish between two people of the same age but different resting heart rates, giving slightly different zone ranges that better match their fitness levels.

Tab 3: Custom Max HR Zones

The Custom Max tab lets you bypass age formulas entirely. You can type in a maximum heart rate measured during an all-out test or obtained from a wearable. The calculator then applies the same percentage-based zone definitions:

This is useful if lab tests, race data or long-term training have already revealed your true max heart rate and you simply want to rebuild the zones from that value.

Tab 4: Workout Zone Planner

The Workout Planner tab takes the formulas one step further and matches them to a chosen workout type. The calculator:

1. Estimates max HR from your age.
2. Optionally uses your resting HR and Karvonen if you select that method or the auto mode chooses it.
3. Assigns an intensity band based on the workout type. For example, Recovery might map to Zone 1, while Intervals map to Zone 4–5.
4. Converts that intensity band to a numeric heart rate range.

This gives you a single target range for a planned session, such as “Run your intervals between 170 and 182 bpm,” rather than a full zone table.

Typical Training Effect Of Each Heart Rate Zone

• Zone 1 (50%–60%): Very easy effort, warm-ups, cool-downs and active recovery.
• Zone 2 (60%–70%): Comfortable, conversational pace that builds aerobic base and improves fat metabolism.
• Zone 3 (70%–80%): Moderate to moderately hard tempo, useful for steady runs and longer efforts.
• Zone 4 (80%–90%): Hard, near-lactate-threshold efforts that improve speed endurance and threshold power.
• Zone 5 (90%–100%): Very hard, short intervals aimed at top-end speed and VO₂max improvements.

The calculator attaches these descriptions to its output so you can quickly see how each zone fits into a training week.

How To Use The Heart Rate Zone Calculator

• Choose the tab that matches your data: age-only, age plus resting heart rate or custom max HR.
• Enter your age and, if available, your resting heart rate measured at complete rest.
• Select your preferred formula and number of decimal places.
• Click the calculate button to generate your zones or workout range.
• Use easier zones for most weekly volume and reserve the hardest zones for shorter, more focused sessions.

Limitations And Safety Notes

All formulas and outputs in this Heart Rate Zone Calculator are estimates meant for education and general training guidance. Individual maximum heart rate and response to exercise can differ significantly from formulas based on age alone.

If you have heart disease, high blood pressure, chest pain, dizziness, breathing problems or any medical condition, you should talk to a healthcare professional before starting or intensifying an exercise plan. Stop exercising and seek help if you feel unwell during a workout, even if your heart rate appears to be inside a calculated zone.