Heart Rate Reserve Target Calculator
Estimate target heart rate using heart rate reserve.
Heart Rate Reserve Target measurements
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Result
How to calculate heart rate reserve target
This calculator uses the Karvonen method to find a target heart rate for a specific exercise intensity, factoring in your resting heart rate rather than just a flat percentage of your maximum — a more personalized approach than simple age-based estimates alone.
How the calculation works
Target heart rate = Resting heart rate + (Maximum heart rate − Resting heart rate) × (Target intensity ÷ 100). The difference between your maximum and resting heart rate is your 'heart rate reserve' — this formula finds the target rate that corresponds to a given percentage of that reserve, added back on top of your resting rate.
Example
With a maximum heart rate of 185 bpm, resting heart rate of 65 bpm, targeting 70% intensity: target = 65 + (185−65) × 0.70 = 65 + 84 = 149 bpm. Compare that to a simple percentage-of-max approach (185 × 0.70 = 129.5 bpm) — the Karvonen method typically produces a higher, more individualized target because it accounts for your specific fitness baseline via resting heart rate.
Frequently asked questions
Why use the Karvonen method instead of just a percentage of max heart rate?
The Karvonen method accounts for your resting heart rate as a baseline, which better reflects individual cardiovascular fitness. Two people with the same maximum heart rate but very different resting rates (say, due to differing fitness levels) will get different, more personalized targets.
How do I find my maximum heart rate accurately?
The common estimate is 220 minus your age, but this has meaningful individual variation. A supervised fitness or stress test provides a more precise number if you need accuracy for a specific training program.
Heart Rate Reserve Target Calculator
Target heart rate = Resting heart rate + (Maximum heart rate − Resting heart rate) × (Target intensity ÷ 100). The difference between your maximum and resting heart rate is your 'heart rate reserve' — this formula finds the target rate that corresponds to a given percentage of that reserve, added back on top of your resting rate.
Let's understand your heart rate reserve target result.
Calculate a result above and this guide will help you interpret it using this calculator's own formula and explanation.
Pro Tips for Heart Rate Reserve Target
- A commonly cited estimate for maximum heart rate is 220 minus your age, though this is a population average with meaningful individual variation — a fitness test or a doctor's guidance gives a more accurate personal number.
- Measure resting heart rate first thing in the morning, before getting out of bed, for the most consistent reading.
- Common training zone guidance: roughly 50–60% intensity for light activity/warm-up, 60–70% for fat-burning/endurance zones, and 70–85% for more vigorous cardio training — check with a trainer or doctor for zones matched to your specific goals and health status.
Common Heart Rate Reserve Target Mistakes to Avoid
- Using an age-estimated maximum heart rate as if it were a measured, precise figure — individual maximum heart rate can vary meaningfully from the 220-minus-age estimate.
- Ignoring medications (like beta-blockers) that directly affect heart rate and can make standard heart-rate-based training zones inaccurate without medical guidance.
When to Use This Calculator
This calculator uses the Karvonen method to find a target heart rate for a specific exercise intensity, factoring in your resting heart rate rather than just a flat percentage of your maximum — a more personalized approach than simple age-based estimates alone.