How this heart rate zone calculator works
Your maximum heart rate (MHR) is the highest number of beats per minute your heart can reach during all-out effort. The simplest and most widely used estimate is MHR = 220 − age, so the figure falls as you get older. It is a population average, not a precise personal measurement — real maximums vary by 10 to 20 bpm from person to person — but it is accurate enough to set sensible training intensities. An alternative is the Tanaka formula, 208 − 0.7 × age, which many researchers consider more accurate for older adults; this tool shows both.
From your maximum, the calculator splits effort into five training zones, each a band of your MHR: Zone 1 very light (50–60%), Zone 2 light (60–70%), Zone 3 moderate/aerobic (70–80%), Zone 4 hard/threshold (80–90%) and Zone 5 maximum (90–100%). If you also enter your resting heart rate, it switches to the Karvonen method, which uses your heart rate reserve: target = ((MHR − resting HR) × intensity %) + resting HR. Because it accounts for fitness, Karvonen usually returns higher, more individual zone numbers.
Reference note: percentages are applied to your estimated maximum heart rate (or to heart rate reserve when a resting value is supplied), and results are rounded to whole beats per minute. These figures are general fitness estimates, not medical advice.
The five zones at a glance
Each zone trains something different — most endurance plans spend the bulk of time in Zones 2 and 3:
| Zone | % of max | What it develops |
|---|---|---|
| Zone 1 — Very light | 50–60% | Warm-up, cool-down and active recovery |
| Zone 2 — Light | 60–70% | Aerobic base, endurance and fat burning |
| Zone 3 — Moderate | 70–80% | Improved aerobic capacity and efficiency |
| Zone 4 — Hard | 80–90% | Lactate threshold and faster sustained pace |
| Zone 5 — Maximum | 90–100% | Peak speed and power in short bursts |
Frequently asked questions
- What is my max heart rate?
- Your maximum heart rate (MHR) is the highest beats per minute your heart can reach during all-out effort. It is most often estimated as 220 minus your age, so a 30-year-old has an estimated MHR of about 190 bpm. This is a population average, not a precise personal measurement, and individuals can be 10 to 20 bpm above or below it.
- What are heart rate zones?
- Heart rate zones are five effort bands set as percentages of your maximum heart rate: Zone 1 very light (50–60%), Zone 2 light (60–70%), Zone 3 moderate or aerobic (70–80%), Zone 4 hard or threshold (80–90%) and Zone 5 maximum (90–100%). Training in different zones develops different things, from easy recovery and endurance to speed and peak performance.
- What is the fat-burning zone?
- The fat-burning zone usually refers to Zone 2, roughly 60–70% of your maximum heart rate. At this easy, conversational pace a higher share of energy comes from fat. However, harder efforts burn more total calories, so for overall fat loss the total energy you expend over time matters more than staying in any single zone.
- What is the Karvonen formula?
- The Karvonen formula uses your heart rate reserve — the gap between your maximum and resting heart rate — to set zones more individually. The target is ((MHR − resting HR) × intensity %) + resting HR. Because it factors in your resting heart rate, it usually gives higher, more personalised zone numbers than a plain percentage of MHR.
- What is a normal resting heart rate?
- For most adults a normal resting heart rate is about 60 to 100 beats per minute, measured when calm and at rest. Well-trained endurance athletes often sit lower, around 40 to 60 bpm. The best time to check is first thing in the morning before getting out of bed.
- Should I consult a doctor?
- Yes. This calculator is for general information and fitness planning only and is not medical advice, diagnosis or treatment. The 220−age formula is an estimate that can be well off for any individual. If you have a heart condition, take medication that affects heart rate, or are new to exercise, talk to a qualified healthcare professional before starting or changing a training program.