Karvonen (heart rate reserve) formula · 5 training zones
Your details
Measure resting heart rate right after waking up, before getting out of bed. If you skip this, we'll use the simpler %-of-max-heart-rate method instead.
These zones are population-average estimates. If you're on heart-rate-affecting medication or have a cardiac condition, talk to your doctor about appropriate training intensity.
How it works
We estimate your max heart rate. Using the standard 220 minus your age formula.
If you gave a resting heart rate, we use the Karvonen formula (heart rate reserve method) for more personalized zones. Otherwise we use simple percentages of your max heart rate.
We calculate 5 zones, from light warm-up (50-60%) up to maximum effort (90-100%), each with a target BPM range.
Use them during exercise. Check your pulse or a fitness tracker against these ranges to gauge intensity.
Max heart rate formulas are population averages with real individual variation (±10-20 bpm is common). For precise numbers, a supervised maximal exercise test is the gold standard.
Frequently asked questions
The Karvonen formula calculates target heart rate using your heart rate reserve (the difference between your max and resting heart rate), rather than just a percentage of your max heart rate alone. It's considered more personalized because it accounts for your fitness level via resting heart rate.
We use the common formula of 220 minus your age. This is a population-average estimate — actual max heart rate varies by individual, and can only be precisely measured with a supervised maximal exercise test.
Your pulse when fully at rest, best measured right after waking up before getting out of bed. Fitter individuals tend to have lower resting heart rates. Including it makes your target zones more personalized than using max heart rate alone.
It depends on your goal: Zone 2 (light) for recovery and base aerobic fitness, Zone 3 (moderate/cardio) for general fitness improvements, and Zone 4-5 (hard/max) for performance and speed work.
No. Certain medications (like beta blockers) and some heart conditions can significantly affect your heart rate response to exercise. If you have a cardiac condition or take heart-rate-affecting medication, talk to your doctor about appropriate training zones.