Target Heart Rate Calculator
Find your training zones in BPM from your age and resting heart rate using the Karvonen method.
Calculation Examples
How to Use the Target Heart Rate Calculator
Enter your age. The calculator estimates your maximum heart rate from it. Then enter your resting heart rate: count your pulse for 30 seconds and double it, or for a full minute, right after waking and before you get out of bed. Averaging three mornings smooths out a bad night. Most adults rest between 60 and 100 bpm, according to the American Heart Association, and well-trained endurance athletes often sit lower.
Next, choose a target intensity as a percentage. About 50-70% suits steady aerobic work and base building, and 80-90% suits hard intervals. Because the Karvonen method works on heart rate reserve, the same percentage gives a higher BPM for a person with a higher resting rate.
The calculator returns BPM ranges for fat-burn, aerobic, and peak zones. It also shows a resting heart rate chart by age and sex so you can see where your baseline sits. The zones are estimates for healthy adults. If you take a beta-blocker or have a heart condition, ask your doctor for your own limits first.
How Target Heart Rate Calculations Work
The calculator uses the Karvonen method (Karvonen et al., 1957), which adds your resting heart rate to the formula instead of using a flat percentage of maximum. It takes three steps.
First, estimate maximum heart rate: \(\text{HR}_{\max} = 220 - \text{age}\). Second, find Heart Rate Reserve: \(\text{HRR} = \text{HR}_{\max} - \text{HR}_{\text{rest}}\). Third, apply your intensity \(I\), written as a fraction such as 0.6 for 60%: \[\text{Target HR} = \text{HRR} \times I + \text{HR}_{\text{rest}}\]
Example: at age 30 with a resting rate of 60 bpm, \(\text{HR}_{\max} = 190\) and \(\text{HRR} = 130\). At \(I = 0.6\), the target is \(130 \times 0.6 + 60 = 138\) bpm. A flat 60% of maximum gives only 114 bpm, so skipping the resting rate puts your zone 24 bpm too low. The 220 minus age rule is a population average with an individual spread of about 10 bpm (Tanaka et al., 2001), so treat every zone as a starting point and adjust it by feel.
Useful Tips 💡
- Measure resting heart rate at the same time each morning and average several days. A single reading swings with sleep, caffeine, and stress.
- Pair the BPM number with the talk test. In an easy aerobic zone you can speak in full sentences; at hard intervals you manage a few words.
- Recalculate when your resting rate changes by 5 bpm or more, or when your age moves up a year or two. Zones drift with fitness.
📋Steps to Calculate
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Enter your age and resting heart rate.
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Select the training intensity percentage that matches your session goal.
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Review your BPM zones and apply them during your workout.
Mistakes to Avoid ⚠️
- Using 220 minus age alone and ignoring resting heart rate. At age 30 with a resting rate of 60 bpm, 60% of maximum is 114 bpm, but the Karvonen target is 138 bpm.
- Treating the 220 minus age estimate as your real maximum. Individual maximums vary by about 10 bpm, and a stress test is the only reliable way to measure yours.
- Trusting a wrist sensor during intervals. Optical sensors often lag or misread when effort changes fast, and a chest strap is more reliable.
- Chasing the peak zone for fat loss. Fat supplies the biggest share of fuel at low to moderate intensity, but fat loss depends on total energy balance, not the zone alone.
Practical Applications📊
Cap easy sessions. At age 40 with a resting rate of 60 bpm, 60-70% of reserve is 132-144 bpm, a ceiling for easy runs and rides.
Plan intervals. At age 30 with a resting rate of 60 bpm, 80-90% of reserve is 164-177 bpm for hard repeats.
Re-check zones as fitness changes. At age 35, dropping resting heart rate from 70 to 60 bpm moves the 70% target from 150.5 to 147.5 bpm.
Check walking intensity. At age 50 the estimated maximum is 170 bpm, so a walk at 95-105 bpm is 56-62% of maximum, inside the moderate range of 50-70% used by the American Heart Association.