Target Heart Rate

Finding Your Target Heart Rate Zones With the Karvonen Method

Your target heart rate zones show what your heart rate should be during exercise at different intensities, based on your estimated maximum heart rate and your resting heart rate. Enter your age and resting heart rate to see your estimated maximum heart rate and four target zones, from a light warm-up pace to vigorous peak effort.

This uses the Karvonen method, which factors in your resting heart rate (not just a flat percentage of your maximum) — generally considered a more personalized estimate, since two people with the same maximum heart rate can have very different resting heart rates depending on fitness level.

The Formula

Maximum heart rate = $220 - \vA{\text{Age}}$ (Fox et al., 1971 — the most widely-used estimate; your real individual maximum can vary). This calculator also shows a second estimate, Tanaka’s formula = $208 - 0.7 \times \vA{\text{Age}}$ (Tanaka, Monahan & Seals, 2001), which a large meta-analysis found more accurate across the lifespan, especially past age 40 — the two estimates diverge more the older you are. Target zones below are calculated from the primary Fox estimate, since it remains the more commonly recognized figure.

Heart rate reserve = $\text{Maximum Heart Rate} - \vB{\text{Resting Heart Rate}}$.

Target heart rate at a given intensity = $\left(\text{Heart Rate Reserve} \times \text{Intensity\%}\right) + \vB{\text{Resting Heart Rate}}$.

Worked Example

A 30-year-old with a resting heart rate of 70 bpm:

1. Maximum heart rate: $220 - 30 = 190$ bpm.
2. Heart rate reserve: $190 - 70 = 120$ bpm.
3. Cardio zone (70-80% intensity): $\left(120 \times 0.70\right) + 70 = 154$ bpm to $\left(120 \times 0.80\right) + 70 = 166$ bpm.

Key Factors to Consider

• The “220 minus age” maximum heart rate formula is a widely-used population average, not a precise individual measurement. Real individual maximum heart rate can vary by 10-20 beats per minute from this estimate for a given age — a fitness professional or a supervised maximal exercise test can measure a specific individual’s actual maximum more precisely than this formula alone. Tanaka’s formula (shown alongside it above) is generally considered a more accurate population estimate, particularly for older adults, but “220 minus age” remains the more commonly recognized figure.
• A lower resting heart rate generally reflects better cardiovascular fitness, and directly affects the calculated target zones. As cardiovascular fitness improves over time, resting heart rate often gradually decreases — periodically re-measuring resting heart rate (rather than using a value from months or years ago) keeps the target zones more accurately calibrated to current fitness level.
• Different exercise goals correspond to different target zones, not one universal “best” intensity. Light activity supports basic health and recovery, moderate cardio zones build aerobic base fitness, and higher-intensity zones develop peak performance and anaerobic capacity — the right zone to target depends on the specific fitness goal, not simply “higher is always better.”
• Certain medications (particularly beta-blockers) can significantly lower heart rate at any given exercise intensity. Someone taking a heart-rate-affecting medication may find their actual heart rate during exercise doesn’t match these calculated zones at all — perceived exertion (how hard the effort genuinely feels) becomes a more reliable intensity guide than heart rate zones in that situation, and this is worth discussing with a healthcare provider.

Common Mistakes

• Using a flat percentage of maximum heart rate instead of heart rate reserve. Zones based purely on maximum heart rate (ignoring resting heart rate entirely) can meaningfully overstate target intensity for a very fit person with a low resting heart rate — the Karvonen method this calculator uses avoids that by factoring resting heart rate in directly.
• Treating a resting heart rate measured after coffee, stress, or activity as accurate. Resting heart rate is only meaningful when measured at true rest, ideally first thing in the morning before getting out of bed — a reading taken later in the day after caffeine or movement runs noticeably higher and skews every zone calculated from it.
• Chasing the highest zone regardless of training goal. More intense isn’t automatically better — building an aerobic base calls for time in the lighter zones, not maximum effort every session.

Useful to Know

• Want a broader picture of your overall fitness level alongside heart rate zones? Body Mass Index (BMI) Calculator and Calorie / TDEE Calculator cover body composition and daily energy needs.
• Training for a running or swimming event and want pace zones to go with heart rate zones? Running Pace Calculator and Swim Pace Calculator cover the equivalent calculations.
• Curious about your aerobic fitness level itself, not just your training zones? VO2 Max Calculator estimates that from a recent race time or heart rate data.