🏃 Heart Rate Zone Calculator: Max Heart Rate and Training Zones (US)

How to use this calculator

1. Enter your age in whole years (18 to 100). Ages outside that range return an out-of-scope message.
2. Choose a maximum heart rate formula: Fox, Tanaka, or a measured maximum from a hard effort or lab test.
3. Optional: enter your resting heart rate in bpm so the calculator can show heart rate reserve and Karvonen zones next to percent-of-max zones.
4. Read the zone table. Each zone has a low and high limit in beats per minute. Use the pulse helper if you need a resting heart rate number first.
5. If you have a heart condition, are pregnant, or take medication that changes heart rate, tick the health note box and still treat every number as educational only.

Maximum heart rate formula options

This max heart rate calculator by age section explains how to calculate max heart rate before you compare zones. HR max means the highest beats-per-minute value your heart is expected to reach during all-out effort. Age-predicted values are estimates, not guarantees.

Both Fox and Tanaka can be off for an individual by many beats per minute. Fitness watches and coach plans sometimes use yet another formula. Treat every age-based number as a starting range, then adjust from how hard the effort actually feels.

Heart rate zones model

Zone labels below use a five-zone calculator convention: Zone 1 at 50–60% of max, Zone 2 at 60–70%, Zone 3 at 70–80%, Zone 4 at 80–90%, and Zone 5 at 90–100%. When your resting heart rate is known, the same percents can also be applied to heart rate reserve with the Karvonen formula, which usually produces higher bpm numbers for the same percent.

Zone 2 heart rate is the zone many easy sessions aim for in popular training plans. Benefit labels are intentionally neutral here: this page does not claim calorie, fat-burning, or disease-prevention effects, because those claims need their own cited primary sources.

Data alternative: the same five bands are listed as low–high bpm pairs in the results table after you calculate, and as percents in the caption above.

Karvonen formula and heart rate reserve

Heart rate reserve is the difference between maximum and resting heart rate. The Karvonen formula (often called the Karvonen formula for target zones) uses that reserve:

Heart rate reserve = maximum heart rate − resting heart rate

Karvonen target bpm = (heart rate reserve × intensity percent) + resting heart rate

Percent-of-maximum target bpm instead uses maximum × intensity. When resting heart rate is entered, this calculator shows both side by side so you can see why the numbers differ. Public-health guidance talks about moderate and vigorous intensity in broad percent terms; always confirm personal targets with a qualified clinician when health conditions or medications are involved. Starting points to check: CDC physical activity pages, American Heart Association target heart rate pages, and the Physical Activity Guidelines for Americans at health.gov.

How to calculate heart rate from a pulse count

Use this pulse helper when you want to calculate heart rate without a chest strap. Count beats for 15, 30, or 60 seconds, then convert to beats per minute. The same helper can feed the resting heart rate field above.

pulse bpm = beats counted × (60 ÷ seconds counted)

Keep this helper purely arithmetic: find a quiet pulse, count steadily, and avoid pressing hard on the neck. If you need clinical guidance on technique or what is normal for you, check the CDC and American Heart Association pages cited under Official references.

Worked examples (hypothetical numbers)

Each example uses clearly labelled hypothetical inputs. Substitutions are shown step by step so you can re-check the arithmetic.

Example A — age 30, Fox formula, percent of max

• Input age = 30 (hypothetical). Fox max = 220 − 30 = 190 bpm.
• Zone 2 (60–70% of max): low = 190 × 0.60 = 114; high = 190 × 0.70 = 133 → 114–133 bpm.
• Tanaka for the same age: 208 − 0.7 × 30 = 187.0 bpm, which is 3 bpm lower than Fox.

Example B — Karvonen with resting 60

• Max = 190, resting = 60 → heart rate reserve = 190 − 60 = 130.
• Zone 3 (70–80% of reserve): low = (130 × 0.70) + 60 = 151; high = (130 × 0.80) + 60 = 164 → 151–164 bpm.
• At the same percents of max, Zone 3 would be 133–152 bpm. Karvonen sits higher because resting heart rate is added back.

Example C — measured max 185, resting 55

• User-measured max = 185, resting = 55 → reserve = 130.
• Karvonen Zone 2: (130 × 0.60) + 55 = 133; (130 × 0.70) + 55 = 146 → 133–146 bpm.

Example D — pulse count

• 35 beats in 30 seconds: 35 × (60 ÷ 30) = 70 bpm.
• 18 beats in 15 seconds: 18 × 4 = 72 bpm.
• 68 beats in 60 seconds: 68 bpm.

Method comparison at a glance

Around age 40 the two formulas cross. Older users often see Tanaka higher than Fox; younger users often see the opposite. Neither line is a personal max.

Common mistakes to avoid

• Trusting an age formula as exact. Fox and Tanaka are averages. Your true max can sit many bpm above or below the line.
• Mixing percent of max with heart rate reserve. “70%” means different bpm numbers under each method. Always check which formula produced the range.
• Measuring resting heart rate at a noisy moment. Right after waking, after caffeine, or mid-stress can shift the number and therefore every Karvonen zone.
• Ignoring medication effects. Beta blockers and other heart-rate-altering drugs can blunt peak and working heart rates. Tick the health note and ask a clinician.
• Treating a zone as medical advice. Zones are training labels, not a diagnosis, prescription, or clearance to exercise.

FAQ

Glossary

HR max (maximum heart rate)

The highest beats-per-minute value expected during all-out effort. Age formulas estimate it; a measured peak is preferred when trustworthy.

Heart rate reserve

Maximum heart rate minus resting heart rate. Used by the Karvonen method to set intensity bands.

Resting heart rate

Beats per minute when fully at rest. Used both for reserve math and as a rough fitness signal over time.

Percent of maximum

Target bpm = maximum × intensity percent. Simple; ignores resting heart rate.

Karvonen formula

Target bpm = (reserve × intensity) + resting. Adds resting heart rate back so low intensities stay meaningful.

Age-predicted maximum heart rate

A population estimate from age alone (Fox or Tanaka). Wide individual variation applies.

Zone 1 to Zone 5

Neutral labels for five 10-percent bands from 50–60% up to 90–100% of the chosen base (max or reserve).

Related topics

If you also track race goals, some people use a separate Race Time Predictor or an Age Calculator for other planning tasks. Those are separate tools; this page stays focused on heart rate zones. Financial planning tools on Varnda (paycheck, loan, credit-card payoff, and mortgage calculators) are unrelated to training zones.

Official references and starting points

Honesty note: no live page was opened on 2026-10-18. The links below are official starting points named for your own check. Treat every citation status as not verified until you open the page yourself.

• CDC — physical activity and target heart rate pages: https://www.cdc.gov/
• American Heart Association — target heart rates: https://www.heart.org/
• Physical Activity Guidelines for Americans: https://health.gov/
• PubMed — Tanaka, Monahan & Seals, “Age-predicted maximal heart rate revisited” (JACC, 2001): start at https://pubmed.ncbi.nlm.nih.gov/
• Karvonen method — confirm against a reputable exercise-physiology textbook or primary paper before citing beyond this educational page.

Byline: Varnda Editorial Team. Corrections: use the site’s contact channel once a public correction address is published; none is invented here.

Limitations, exclusions, and assumptions

• Population formulas are estimates. No accuracy guarantee is claimed.
• Medical advice, cardiac screening, exercise stress tests, medication modeling, pregnancy-specific targets, and heart rate variability are out of scope.
• Five-zone bands are a calculator convention, not an official standard. Zone labels are neutral.
• Calories, fat-burning, and disease claims are omitted unless a primary source is opened and cited in a future update.
• Under-18 and over-100 ages return outside calculator scope.
• Resting heart rate must be 30–120 bpm and below the maximum used for reserve math.