Knowing your target heart rate is the simplest way to train at the right intensity. If you push too gently, you waste your workout; if you push too hard, you burn out, risk injury, or cut a session short. This calculator uses the classic American Heart Association (AHA) method to turn your age into two practical zones — a moderate zone at 50–70% of your maximum heart rate and a vigorous zone at 70–85% — then gives you the exact beats-per-minute (bpm) you should aim for at the intensity you choose.
Slide the controls and the result card updates instantly. Whether you are walking, jogging, cycling, on an elliptical, or taking a group class, you can match your effort to a number on your watch and stop guessing whether you are actually getting the benefit you want.
How to Use
- Enter your Age in years. The formula estimates your maximum heart rate as 220 minus your age, which is the reference the AHA uses for its public target heart rate table.
- Enter your Resting Heart Rate (RHR) in bpm. Measure it first thing in the morning before you get out of bed, before coffee, after a normal night of sleep. The calculator uses this in the Karvonen heart-rate-reserve method, which is more precise than a flat percentage of max HR.
- Set the Exercise Intensity to how hard you plan to work. Choose 50–60% for an easy walk or warm-up, 60–70% for steady cardio you can sustain, and 70–85% for running or intervals.
- Read the result card. It first shows your Maximum Heart Rate and Heart Rate Reserve (max minus resting), then the AHA Moderate (50–70%) and Vigorous (70–85%) bands, and finally Your Target Heart Rate (Karvonen) — the single bpm that matches your intensity, computed as resting HR plus your HRR times the intensity percentage.
- Check the Effort Zone code. 1 = Light (<50%), 2 = Moderate (50–70%), 3 = Vigorous (70–85%), 4 = Maximum (>85%).
- During exercise, warm up for 5–10 minutes, then check your pulse (wrist or neck) for 15 seconds and multiply by four, or glance at a chest strap or watch. Compare that number to your target.
- If your measured pulse is below the moderate lower bound, speed up or add resistance. If it rises above the vigorous upper bound, ease back until it settles into your zone.
You do not need to be an athlete to benefit. Even brisk walking at the moderate zone improves cardio fitness, blood pressure, and cholesterol, and the AHA recommends most adults accumulate 150 minutes of moderate activity each week.
The Target Heart Rate Formula
The method behind this calculator comes straight from the AHA's target heart rate guidelines:
Maximum Heart Rate = 220 − Age
From that ceiling, the AHA defines two intensity bands:
- Moderate intensity = 50% to 70% of your maximum heart rate
- Vigorous intensity = 70% to 85% of your maximum heart rate
Your personal target heart rate at any chosen effort uses the Karvonen heart-rate-reserve method:
Target HR = Resting HR + (Max HR − Resting HR) × Intensity %
This is more precise than a flat percentage of max HR because it rewards a low resting pulse with a lower, more realistic training target. The AHA still publishes the 50–70% and 70–85% bands as percentages of max HR, so the calculator shows both: the AHA bands on the left (percent of max HR) and your Karvonen target on the right (percent of heart-rate reserve).
Worked example for a 35-year-old with a resting heart rate of 70 bpm: maximum heart rate is 220 − 35 = 185 bpm. The AHA moderate band is 185 × 0.50 = 93 bpm up to 185 × 0.70 = 130 bpm. The vigorous band runs from 130 bpm up to 185 × 0.85 = 157 bpm. Heart rate reserve is 185 − 70 = 115 bpm. At 60% intensity, the Karvonen target is 70 + 115 × 0.60 = 139 bpm — slightly above the AHA moderate upper bound, because a resting HR of 70 is on the higher side and the reserve method pushes the target up.
The 220-minus-age rule is a population estimate, not a personal guarantee. Real maximum heart rate varies by fitness, genetics, medications, and altitude, so treat these numbers as a starting range and adjust based on how you feel and what your measured pulse tells you.
Moderate vs Vigorous: Which Zone Should You Use?
Both zones count toward fitness, but they suit different goals and fitness levels:
- Moderate zone (50–70%) — you can talk in full sentences but cannot sing. This is the band for brisk walking, casual cycling, swimming laps at an easy pace, and recovering between harder efforts. It is the safest starting point for beginners and the recommended base for the AHA's 150-minute weekly target.
- Vigorous zone (70–85%) — you can only speak in short phrases. This is running, fast cycling, stair climbing, and interval training. It builds cardiovascular endurance faster, but it is harder on the body and should be built toward gradually.
A sensible mix is to spend most of your sessions in the moderate zone and add one or two shorter vigorous sessions per week once your base fitness is established. Beginners should anchor on the moderate lower bound and work up; experienced exercisers can push into the vigorous band for speed and endurance gains.
Examples
Example 1 — A 35-year-old jogging at moderate effort. Age 35, resting HR 70, intensity 60%. Maximum heart rate is 185 bpm, heart rate reserve is 115 bpm, and the Karvonen target is 70 + 115 × 0.60 = 139 bpm. The AHA moderate band is 93–130 bpm; the Karvonen moderate lower bound (50% HRR) is 128 bpm. The effort zone reads Moderate.
Example 2 — A 50-year-old brisk walker. Age 50, resting HR 70, intensity 65%. Maximum heart rate is 170 bpm, HRR is 100 bpm, and the Karvonen target is 70 + 100 × 0.65 = 135 bpm. The AHA moderate band spans 85–119 bpm and the vigorous band 119–145 bpm, so 135 lands in the lower vigorous range by the AHA table.
Example 3 — A 40-year-old runner doing intervals. Age 40, resting HR 55, intensity 75%. Maximum heart rate is 180 bpm, HRR is 125 bpm, and the Karvonen target is 55 + 125 × 0.75 = 149 bpm. The AHA vigorous band spans 126–153 bpm; the trained athlete's low resting HR pulls the Karvonen target down slightly inside that band.
Example 4 — A trained athlete with a low resting HR. Age 40, resting HR 45, intensity 70%. Max HR is 180, HRR is 135, and the Karvonen target is 45 + 135 × 0.70 = 139.5 ≈ 140 bpm. A fitter person with a resting pulse of 45 gets a lower training target than someone the same age with a resting pulse of 70, which is the whole point of the reserve method.
FAQ
What is a good target heart rate when exercising?
For most adults, moderate exercise keeps your heart between 50% and 70% of its maximum, and vigorous exercise between 70% and 85%. Maximum heart rate is estimated as 220 minus your age. Enter your age and chosen intensity above to see the exact bpm range for you.
How do I calculate my target heart rate?
First estimate your maximum heart rate as 220 minus your age, then measure your resting heart rate first thing in the morning. Subtract resting from max to get your heart-rate reserve, and add resting back after applying your intensity percentage: Target = Resting + (Max − Resting) × Intensity %. This Karvonen method is what the calculator uses. The AHA still publishes 50–70% (moderate) and 70–85% (vigorous) bands as percentages of max HR for quick reference.
What heart rate zone is considered moderate?
Moderate intensity is 50% to 70% of your maximum heart rate. At this level you can talk in sentences but cannot sing. It includes brisk walking, easy cycling, and casual swimming, and it is the band the AHA recommends for the 150 minutes of weekly activity most adults need.
What heart rate zone is considered vigorous?
Vigorous intensity is 70% to 85% of your maximum heart rate. At this level you can only speak in short phrases. It includes running, fast cycling, stair climbing, and interval training, and it builds endurance more quickly but should be built up to gradually.
Is 220 minus age accurate for maximum heart rate?
It is the standard population estimate used by the AHA, but real maximum heart rate varies. Fitness level, genetics, medications, and altitude all affect it. Some formulas (such as 208 − 0.7 × age) give slightly different averages. Use 220 minus age as a starting range and adjust based on how you feel.
What if my heart rate is above the vigorous zone during exercise?
If your pulse climbs above 85% of your maximum while you are not doing high-intensity intervals, slow down. Pushing continuously beyond the vigorous zone raises fatigue and injury risk. Ease back until your pulse settles into the moderate or vigorous band, and check in with your doctor if this happens unexpectedly at low effort.
Can I use target heart rate if I take heart medication?
Some medications, such as beta-blockers, lower your heart rate and make heart-rate targets unreliable. If you take heart medication, talk to your doctor before using heart-rate zones to train. The talk test — you can hold a conversation at moderate effort — is often a safer guide in that situation.
Disclaimer
This target heart rate calculator is provided for informational purposes only and is not medical advice. The 220-minus-age formula produces population estimates, not individualized diagnoses or prescriptions. Results vary by fitness, genetics, medications, and health conditions. If you have a heart condition, are pregnant, have been sedentary, or experience chest pain, dizziness, or unusual shortness of breath during exercise, consult a qualified healthcare professional before starting or changing an exercise program. Always exercise within your own comfort level.