Heart Rate Calculator
Estimate your maximum heart rate and target heart-rate training zones, using either the simple percentage method or the more personalised Karvonen (heart rate reserve) method.
Tanaka (2001) is a widely used alternative to the older 220−age formula, developed from a large meta-analysis of healthy adults. Gulati (2010) was derived specifically from women’s exercise test data.
The Karvonen method factors in your resting heart rate above, giving a more personalised zone — it needs a resting heart rate to be entered.
Your Target Heart Rate Zones
Moderate & Vigorous Activity
The NHS recommends at least 150 minutes of moderate-intensity activity a week, or 75 minutes of vigorous-intensity activity, or a combination of both. The NHS’s own practical check is the “talk test”, shown below — the bpm figures are illustrative estimates commonly used elsewhere, not official NHS heart-rate thresholds.
Heart Rate Calculator UK
Our Heart Rate Calculator estimates your maximum heart rate and target heart-rate training zones, so you can gauge exercise intensity more precisely than “how hard does this feel”. Choose from three published maximum-heart-rate formulas, and calculate your zones using either a simple percentage method or the more personalised Karvonen (heart rate reserve) method, which factors in your resting heart rate. These are formula-based estimates for general fitness use, not a medical assessment.
How Is Maximum Heart Rate Calculated?
There’s no way to know your true maximum heart rate without a supervised maximal exercise test — every formula is an estimate based on population averages, and individual results can differ by 10 to 15 bpm or more from any prediction. This calculator offers three commonly used formulas:
| Formula | Equation | Notes |
|---|---|---|
| Classic (Fox, 1971) | 220 − age | The most widely known formula, but research suggests it can be less accurate, particularly for older adults. |
| Tanaka (2001) | 208 − (0.7 × age) | A widely used alternative to the 220-age formula, developed from a meta-analysis of over 18,000 people. |
| Gulati (2010) | 206 − (0.88 × age) | Derived specifically from women’s exercise stress test data. |
Percentage Method vs Karvonen (Heart Rate Reserve) Method
The simple percentage method sets each training zone as a straight percentage of your maximum heart rate. The Karvonen method instead uses your heart rate reserve — the gap between your maximum and your resting heart rate — because a fitter person generally has a lower resting heart rate, which the simple percentage method doesn’t account for. The Karvonen formula for a given intensity is: Target HR = ((Max HR − Resting HR) × Intensity%) + Resting HR. It generally produces higher target values than the simple percentage method at the same stated intensity.
Understanding the Five Training Zones
- Zone 1 (50–60%) — Warm Up / Recovery: Very light effort, used for warming up, cooling down, or active recovery days.
- Zone 2 (60–70%) — Easy / Aerobic: A pace you can sustain for a long time; builds aerobic base fitness.
- Zone 3 (70–80%) — Aerobic / Endurance: A steady, moderately hard effort that improves cardiovascular fitness.
- Zone 4 (80–90%) — Threshold / Hard: Hard efforts that raise the intensity you can sustain before fatigue builds quickly.
- Zone 5 (90–100%) — Maximum / Anaerobic: Short, maximal-effort intervals, sustainable only briefly.
Moderate vs Vigorous Intensity: The NHS Guidelines
The NHS recommends adults do at least 150 minutes of moderate-intensity activity a week, or 75 minutes of vigorous-intensity activity, or a combination of both. Rather than a specific heart rate figure, the NHS’s own practical guide is the “talk test”: during moderate activity you can still talk but not sing, and during vigorous activity you can only manage a few words before pausing for breath. Commonly cited heart-rate ranges for these categories are roughly 50–70% of your maximum heart rate for moderate intensity, and 70–85% for vigorous intensity.
What Affects Your Heart Rate?
- Medication: Beta blockers and some other heart or blood pressure medications lower both resting and maximum heart rate significantly — these formulas will not apply to you if you take them.
- Fitness level: Regular training tends to lower resting heart rate over time, which is why the Karvonen method can give a more personalised picture than a simple percentage.
- Heat, altitude, dehydration and illness can all raise your heart rate at a given effort level.
- Age and individual biology: All formulas are population averages — genetics mean two people of the same age can have genuinely different true maximums.
Frequently Asked Questions
Which maximum heart rate formula is most accurate?
None of them is exact for every individual — they’re all population-based estimates. The Tanaka formula (208 minus 0.7 times age) is a widely used alternative to the older 220-minus-age formula, developed from a large meta-analysis of healthy adults, while the Gulati formula was derived specifically from women’s exercise test data. The only way to know your true maximum is a supervised maximal exercise test.
What is the Karvonen method and why does it need my resting heart rate?
The Karvonen method calculates target heart rate as a percentage of your heart rate reserve (maximum heart rate minus resting heart rate) rather than a percentage of maximum heart rate alone. Because it incorporates your resting heart rate, the Karvonen method can provide a more individualised estimate than using maximum heart rate alone.
What is a normal resting heart rate?
A normal resting heart rate for most adults is between 60 and 100 beats per minute, though well-trained athletes often have lower resting heart rates, sometimes in the 40s or 50s. Measure it first thing in the morning, before getting up, for the most consistent reading.
Do the NHS activity guidelines use an exact heart rate target?
Not officially. The NHS recommends at least 150 minutes of moderate-intensity activity a week or 75 minutes of vigorous-intensity activity, and its own practical check is the “talk test” — whether you can talk but not sing (moderate), or can only say a few words before pausing (vigorous). Heart-rate percentage ranges for these categories are commonly cited by other health organisations rather than being an official NHS numeric standard.
Can I use this if I take beta blockers or have a heart condition?
These formulas and zones are based on data from the general population and don’t account for heart-rate-affecting medication or diagnosed heart conditions. If you take beta blockers or another medication that affects heart rate, or you have a cardiac condition, please speak to your GP or cardiologist for guidance specific to you rather than relying on these estimates.
Why is my target heart rate higher with the Karvonen method than the percentage method?
The Karvonen method calculates a percentage of your heart rate reserve and then adds your resting heart rate back on top, rather than taking a percentage of maximum heart rate alone. Because resting heart rate is added at the end, Karvonen figures are typically a few beats per minute higher than the simple percentage method at the same stated intensity, especially at lower intensities.