Heart Rate Zone Calculator
Find your maximum heart rate and your five training zones — from warm-up to maximum effort — based on your age. Add your resting heart rate to use the more personalised Karvonen method.
Resting, maximum and target heart rate
Your heart rate — beats per minute — is a simple window into how hard your body is working. Two reference points anchor everything else. Your resting heart rate is your pulse when you're calm and still; for most adults it sits around 60–100 bpm, and fitter people often dip lower. Your maximum heart rate is the fastest your heart can safely beat during all-out effort, which falls naturally with age. Between those two lie your target heart-rate zones — bands of intensity you can train in deliberately to get specific results, from easy recovery to flat-out sprinting.
This calculator estimates your maximum heart rate from your age, then maps out five training zones. Add your resting heart rate and it switches to a more personalised method for sharper targets.
How to use this calculator
Enter your age to get an estimated maximum heart rate and your five zones as bpm ranges. If you know your resting heart rate — best measured first thing in the morning before getting up — add it, and the calculator uses the Karvonen heart-rate-reserve method, which tailors the zones to your individual fitness. Use a chest strap, wrist tracker or a manual pulse count to check which zone you're actually training in during a workout.
How it's calculated
The classic estimate for maximum heart rate is 220 − age. It's easy to remember but only a rough population average. The Tanaka formula, 208 − (0.7 × age), is generally more accurate, particularly for older adults, where "220 − age" tends to under-estimate. Zones are then set as percentages of that maximum. The more personalised Karvonen method uses your heart-rate reserve — the gap between maximum and resting — like this: target = (max − resting) × intensity% + resting. Because it factors in your resting rate, two people the same age get different zone targets if their fitness differs.
Worked example
For a 40-year-old, Tanaka gives a max of 208 − (0.7 × 40) = 180 bpm. A simple 70% target is 126 bpm. With Karvonen and a resting rate of 60 bpm, the same 70% intensity is (180 − 60) × 0.70 + 60 = 144 bpm — noticeably higher, because the method anchors to their actual resting pulse.
| Zone | % of max HR | Feels like | Used for |
|---|---|---|---|
| Zone 1 — Very light | 50–60% | Easy, can chat freely | Warm-up, recovery |
| Zone 2 — Light | 60–70% | Comfortable, steady | Aerobic base, fat use |
| Zone 3 — Moderate | 70–80% | Breathing harder | Aerobic fitness, endurance |
| Zone 4 — Hard | 80–90% | Tough, short sentences | Speed, lactate threshold |
| Zone 5 — Maximum | 90–100% | All-out, unsustainable | Peak power, sprints |
Limitations & tips
Every formula here is a population estimate, and real maximum heart rates vary by 10–20 bpm or more between individuals of the same age — the only precise way to know yours is a supervised exercise test. Medications such as beta-blockers can lower your heart rate substantially and make these zones inaccurate. Build most training in the lower, sustainable zones and use the hard zones sparingly. Importantly, this information is not medical advice: see a doctor before starting vigorous exercise if you're older, out of shape or have a health condition, and seek prompt medical attention for a persistently very high or very low resting pulse, a markedly irregular heartbeat, or symptoms like chest pain, fainting, severe breathlessness or dizziness during activity.
Frequently asked questions
How is maximum heart rate calculated?
The common estimate is 220 minus your age. The Tanaka formula (208 − 0.7 × age) is often more accurate for older adults. Both are population estimates; an exercise test measures your true maximum.
What is the Karvonen method?
Karvonen uses your heart-rate reserve — the gap between your maximum and resting heart rate — to set zones: target = (max − resting) × intensity + resting. It personalises zones to your fitness, so add your resting heart rate if you know it.
Which heart rate zone burns the most fat?
The 60–70% zone is often called the 'fat-burning' zone because fat fuels a larger share of energy there. Higher-intensity work burns more total calories, though, so mixing zones tends to work best for fat loss.
What's a normal resting heart rate?
For most adults it's about 60–100 beats per minute, and well-trained people are often lower. The best time to measure is first thing in the morning before you get up. A consistently very high or very low resting rate is worth discussing with a doctor.
How accurate is the 220 − age formula?
It's a quick estimate, not a measurement, and can be off by 10–20 bpm for any given person. The Tanaka formula (208 − 0.7 × age) tends to be more accurate, especially for older adults. A supervised exercise test is the only way to find your true maximum.
When should an unusual heart rate prompt a doctor's visit?
See a healthcare professional for a persistently very high or very low pulse, a heartbeat that feels markedly irregular or skips, or any chest pain, fainting, severe breathlessness or dizziness during exercise. These can signal conditions that need proper evaluation rather than self-assessment.
Sources & references
- American Heart Association — Target Heart Rates Chart — the classic 220 − age estimate and percentage-of-max training zones this calculator is built around.
- Tanaka H, Monahan KD, Seals DR — "Age-predicted maximal heart rate revisited," J Am Coll Cardiol (2001) — source of the 208 − 0.7 × age formula this calculator offers as a more accurate alternative.
Last updated: July 2026 · How we calculate
BriskToolbox provides estimates for general information only and is not medical advice. Talk to a healthcare professional about your individual health.