The Target Heart Rate Calculator estimates maximum heart rate from age, then maps five training zones as percentages of that maximum or, when resting heart rate is entered, as Karvonen heart-rate reserve bands. Choose Tanaka, Fox (220 minus age) or Gulati, read the zone table in beats per minute, and treat every figure as an estimate with real individual scatter.
Heart-rate zones are coaching aids, not diagnoses. A zone labelled moderate describes an intensity band on a chart; it does not declare that a specific workout was safe or optimal for a specific person. Anyone with a heart condition, or anyone new to intense exercise, should get medical clearance before training by these numbers.
Calculate your target heart rate zones
Target zones are ranges of beats per minute used to guide warm-up, endurance and harder efforts.
The Target Heart Rate Calculator first estimates maximum heart rate from age and a chosen formula, then applies the five zone percentages stored in the health reference: 50 to 60, 60 to 70, 70 to 80, 80 to 90 and 90 to 100 percent of maximum, or the same percentages of heart-rate reserve when resting rate is known.
Enter age, optionally resting heart rate in bpm, and a max-HR formula. Without a resting rate, zones are simple percentages of estimated maximum. With a resting rate, zones use the Karvonen method, which usually produces higher absolute bpm targets for the same percentage labels because reserve starts from rest rather than from zero.
The result is general information for planning, not medical advice. Wrist and chest monitors disagree slightly; use a consistent device when comparing sessions.
Estimate your maximum heart rate
Maximum heart rate falls with age on average, but formulas disagree and individuals scatter widely. Three estimates ship from the reference file:
| Label | Formula | Note |
|---|---|---|
| Fox | 220 − age | Common rule of thumb; scatter often about ±10 to 12 bpm |
| Tanaka | 208 − 0.7 × age | Often closer across ages, especially older adults |
| Gulati | 206 − 0.88 × age | Derived on women |
Tanaka is the default because it tends to track measured maxima better than 220 minus age for many adults. Fox remains available because many plans still quote it. Gulati is offered for users who want the women-derived equation.
No laboratory test sits behind these equations. A true maximum usually needs a supervised graded exercise test. Formula maxima are planning anchors; if a wearable regularly records higher or lower peaks in hard efforts, the field data often matter more than the chart.
Apply the Karvonen formula
Karvonen intensity uses heart-rate reserve, the gap between maximum and resting rate:
target = ((maxHR − restingHR) × intensity) + restingHRIntensity is the zone fraction (for example 0.70 for the low edge of zone 3). Compared with percent-of-max alone, Karvonen raises the bpm floor for a given percentage when resting rate is low, and it personalises the band to how high the pulse sits at rest.
Resting heart rate is best taken seated or lying, after several quiet minutes, ideally in the morning before caffeine. A single rushed reading inflates rest and compresses reserve, which pushes every zone upward. Recheck periodically; fitness and illness both move resting rate.
If resting rate is omitted, the calculator falls back to percent of estimated maximum. That mode is simpler and less personalised; both modes share the same five zone labels and purposes from the reference table.
Read the five training zones
Five zones describe intensity from very light to maximum. Purposes below match the health reference; they are coaching shorthand, not clinical categories.
| Zone | Percent of max or reserve | Label | Typical purpose |
|---|---|---|---|
| 1 | 50 to 60% | Very light | Warm-up, recovery |
| 2 | 60 to 70% | Light | Base endurance |
| 3 | 70 to 80% | Moderate | Aerobic fitness |
| 4 | 80 to 90% | Hard | Anaerobic threshold, performance |
| 5 | 90 to 100% | Maximum | Short intervals, peak effort |
Zone 2 often carries a "fat burning" label in consumer apps. Fat contributes a larger share of fuel at easier intensities, but total calories and training effect still depend on duration and fitness. The page keeps the reference wording ("Fat burning, base endurance") without treating zone 2 as a weight-loss prescription.
Spend most endurance volume in easier zones and reserve zone 4 and 5 for short, purposeful work. That distribution is a common training pattern, not a rule that fits every sport or every medical history.
Calculate zones for a 40-year-old
Take an adult aged 40 with a resting heart rate of 60 bpm, using Tanaka as the max formula. This is the worked fixture for the page. 1. Estimate maximum heart rate (Tanaka). 208 − 0.7 × 40 = 208 − 28 = 180 bpm
2. Compare the other formulas at the same age. Fox: 220 − 40 = 180 bpm (same as Tanaka at age 40; the formulas diverge at other ages) Gulati: 206 − 0.88 × 40 = 206 − 35.2 ≈ 171 bpm
3. Build Karvonen zones with max 180 and rest 60. Reserve = 180 − 60 = 120 bpm. Then:
| Zone | Intensity | Karvonen range (bpm) |
|---|---|---|
| 1 Very light | 50 to 60% | 120 to 132 |
| 2 Light | 60 to 70% | 132 to 144 |
| 3 Moderate | 70 to 80% | 144 to 156 |
| 4 Hard | 80 to 90% | 156 to 168 |
| 5 Maximum | 90 to 100% | 168 to 180 |
Percent-of-max bands at 180 bpm without Karvonen would read about 90 to 108, 108 to 126, 126 to 144, 144 to 162 and 162 to 180. The Karvonen set sits higher in the lower zones because it starts from resting rate.
What this does not tell you: whether 180 bpm is this person's true maximum, whether zone 3 is appropriate on a given day, or whether a heart condition changes safe limits. It tells you the chart values for those inputs.
Train in the right zone for your goal
Match the zone to the job. Recovery days and warm-ups belong near zone 1. Long aerobic base work usually lives in zone 2 and easy zone 3. Tempo and threshold sessions push into zone 4 for limited time. Zone 5 is for short intervals with full recovery, not for hour-long grinds.
Goals such as finishing a first 5K, building marathon endurance or returning after a break all tolerate more easy volume than ego suggests. Pairing zone targets with the Pace Calculator helps when a race plan needs both a pace and an effort ceiling.
Stop and seek care for chest pain, unexplained dizziness, severe breathlessness or other warning symptoms. Zone charts do not override those signals. The estimate on this page is for general fitness planning; it is not a personal exercise prescription.
Frequently asked questions
What is a target heart rate?
A target heart rate is a bpm range chosen to represent a training intensity, usually as a percentage of estimated maximum heart rate or of heart-rate reserve. The five zones on this page are one common layout from 50% to 100%.
Is 220 minus age accurate?
It is a rough population rule with wide individual scatter, often cited around ±10 to 12 bpm. Tanaka (208 − 0.7 × age) is the default here because it often fits measured maxima better across ages. At age 40 both Fox and Tanaka give 180 bpm; they diverge at other ages.
What is the Karvonen method?
Karvonen sets target = ((maxHR − restingHR) × intensity) + restingHR. It uses heart-rate reserve so resting rate personalises the zones. Enter resting bpm to switch from percent-of-max to Karvonen on this tool.
What resting heart rate should I use?
Use a quiet morning reading when possible, seated or lying, before stimulants. Average a few days if readings jump around. An inflated resting rate shrinks reserve and pushes zone bpm upward.
Do the zones diagnose fitness?
No. Zones describe intensity bands for planning. They do not diagnose cardiovascular disease, VO₂ max or training readiness. Fitness testing and clinical decisions belong with qualified professionals.
Should I exercise in zone 2 to lose fat?
Zone 2 uses a higher share of fat for fuel at that intensity, but fat loss over weeks depends on overall energy balance and habits, not on staying in one zone. Treat zone 2 as base endurance work, not as a weight-loss prescription.
When do I need medical clearance?
Before intense training if there is known heart disease, concerning symptoms, or little recent activity after a long break. Max-HR formulas are estimates; clearance is a clinical judgement, not something a calculator can grant.
Which formula should women use?
Gulati (206 − 0.88 × age) was derived on women and is available as an option. Tanaka remains a solid default for many adults of any sex. Compare formulas if useful, and prefer field data from hard efforts when they clearly disagree with the chart.
Summary
The Target Heart Rate Calculator estimates maximum heart rate with Tanaka, Fox or Gulati, then maps five zones by percent of maximum or by Karvonen reserve when resting rate is entered.
For age 40, Tanaka gives 180 bpm; with resting 60 bpm, Karvonen zones run from about 120 to 132 bpm in zone 1 up to 168 to 180 bpm in zone 5.
Formulas scatter across individuals by a wide margin. Zones are planning estimates for general information, not medical advice, and intense training may require clinician clearance first.