Target Heart Rate Calculator - Fox, Tanaka, Karvonen

A target heart rate calculator turns age (and optionally resting pulse) into a grid of beats per minute. The default Fox equation is HRmax = 220 − age. At age 30 that is 190 bpm. Seventy percent of that HRmax is 0.70 × 190 = 133 bpm. Tanaka’s optional alternative is 208 − 0.7 × age = 208 − 21 = 187 bpm at age 30. Zones on this page are 50–60, 60–70, 70–80, 80–90, and 90–100 percent of estimated HRmax. They are a teaching lattice, not a guarantee of “fat burn,” lactate threshold, or VO2max for you.

Karvonen (heart-rate reserve) needs a resting HR: target = (HRmax − HRrest) × fraction + HRrest. Default rest 60 and Fox 190 give a reserve of 130; at 70% Karvonen is 60 + 0.7 × 130 = 151 bpm, higher than 133 because reserve scales the working range above rest. If you clear resting HR, the Karvonen column disappears. Measure rest seated after several quiet minutes, not immediately after coffee or a set of stairs.

Scatter around 220 − age is large. Some 30-year-olds have true HRmax well above or below 190. Gulati and other sex- specific formulas exist; they are not the default here so the page stays inspectable. A treadmill stress test with ECG is a different medical procedure. This form does not interpret ST segments, symptoms, or medications.

Pairing ideas, not prescriptions: easy running often lives nearer conversational effort than a zone number; see the pace calculator for clock math. Bout energy cost is the calories burned calculator. Strength loading is the one-rep max calculator.

1. Enter age. Fox HRmax is 220 minus that integer. Default 30 → 190.
2. Optionally enter resting heart rate for Karvonen. Default 60 → 70% Karvonen 151 with Fox 190.
3. Optionally show Tanaka beside Fox so you can see both %HRmax columns.
4. Copy if needed. Beta blockers and illness override these numbers. Inputs stay in this browser 30 days. Not medical advice.

Fox zones at 190: 50–60% is 95–114, 60–70% is 114–133, 70–80% is 133–152, 80–90% is 152–171, 90–100% is 171–190 (rounding to whole bpm). Adjacent bands share an edge; treat the boundary as a smear, not a cliff. Karvonen Fox with rest 60: 50% is 60 + 0.5 × 130 = 125; 70% is 151; 90% is 60 + 0.9 × 130 = 177. Notice 50% Karvonen (125) is already above 50% HRmax (95). People who quote “zone 2” without saying %HRmax versus reserve are talking past each other.

Tanaka 187 at age 30: 70% HRmax = 131; Karvonen 70% = 60 + 0.7 × (187 − 60) = 60 + 88.9 = 148.9. The gap between Fox and Tanaka is a few bpm at 30 and grows or shrinks with age because the slopes differ (1.0 vs 0.7 per year).

Worked extras: age 50 Fox HRmax = 170; 70% = 119. Age 50 rest 70, Karvonen 70% = 70 + 0.7 × 100 = 140. Age 20 Fox = 200; 70% = 140. Age 40 Tanaka = 208 − 28 = 180. Those are algebra drills, not training orders.

Beta-adrenergic blockers blunt heart-rate rise. Age-predicted HRmax and Karvonen then describe a person who is not on the drug. Other rate-limiting agents, some antidepressants, and dehydration shift the curve. Caffeine and fever raise rest. Wrist optical sensors lag and slip on dark tattoos or cold skin; a chest strap is usually cleaner for intervals, still not a 12-lead ECG.

Chest pain, unexplained dyspnea, syncope, or a sudden drop in achievable heart rate need clinical evaluation, not a tighter zone chart. We will not tell you it is safe to ignore symptoms because “you were only in zone 2.”

Pregnancy, pediatric cardiology, and known arrhythmia belong with specialists. This adult teaching grid should not be pasted onto those populations.

Five-zone percent grids predate cheap lactate meters and metabolic carts. Lactate threshold and ventilatory thresholds do not sit at the same %HRmax for everyone. Polarized or pyramidal training debates are coaching philosophy. This page will not pick a camp. “Maximum heart rate” itself is protocol-dependent (incremental test vs field sprint).

Search queries: “target heart rate 30 years old,” “Karvonen formula,” “220 minus age.” Age 30 Fox is 190; 70% is 133; Karvonen with rest 60 is 151. That is the entire default story. Fitness watches that emit a custom HRmax from workouts may be closer for you than Fox-still not medical clearance.

Adult mass screening remains a different tool: the BMI calculator. Due dates are the due date calculator. Use the matching question.

Resting heart rate for Karvonen should be taken seated or supine after several quiet minutes, ideally a morning average over a few days. A single 48 bpm reading after endurance training and extra sleep is not the same as 72 bpm during a stressful workweek. If rest jumps 15 bpm with fever or overreaching, do not keep using last month’s 60 in the formula as if physiology were frozen. This page will not average a week of wearables for you.

Atrial fibrillation and other irregular rhythms make optical wrist sensors noisy. Do not treat a flickering 90–140 watch trace as a clean HRrest for Karvonen. Clinical devices and clinicians exist for that. We will not diagnose arrhythmia from a number you typed.

Field tests that “find HRmax” by sprinting up a hill are unsupervised maximal efforts. This calculator will not prescribe them. If you already have a test-derived HRmax from a lab, you can still use Karvonen by… not using Fox: the identity (HRmax − rest) × f + rest works with any HRmax you supply conceptually, but this UI only offers Fox and Tanaka so it cannot be mistaken for a place to paste a stolen hospital PDF.

Swimming heart rate is often lower than running at similar perceived effort because of posture and cooling. Cycling sits in between for many people. Applying a running-derived Fox table to a long swim is a category error. The pace calculator is running clock math only; this HR page is pulse math only. Keep them in their lanes.

Unique 30-day localStorage remembers age, rest, and whether Tanaka is shown. That is not a training log of session peaks. If medications change, update rest and treat Fox as even more suspect. Medical clearance for vigorous exercise in people with known disease is a clinician’s job, not a green checkmark next to 133 bpm.

Search queries: “target heart rate for 30 year old,” “Karvonen 70 percent,” and “220 minus age.” The default answers are 190, 151, and 190 respectively, with 70% of Fox HRmax at 133. A 40-year-old Fox HRmax is 180; 70% is 126; Tanaka is 208 − 28 = 180 coincidentally the same as Fox at age 40 because 220 − 40 = 180 and 208 − 0.7×40 = 180. Ages where Fox and Tanaka match are a curiosity of two lines crossing, not a special birthday. At 60, Fox is 160 and Tanaka is 208 − 42 = 166.

Wrist-based “cardio fitness” scores and recovery hours are vendor products. They may use resting HR, but they are not Karvonen zone tables. Do not average a watch’s zone 2 with this page’s 60–70% Fox band and call it science. If you use talk-test or nasal-breathing rules for easy work, those are perception tools that can disagree with 133 bpm on a hot day. Perception plus caution beats a single default table when you feel unwell.

Fox’s 220 − age is easy to memorize and easy to miss by 10–20 bpm in individuals. Endurance athletes sometimes show lower resting HR and still hit high maximal rates; untrained adults may not reach predicted HRmax on a bike because legs fail first. Tanaka 208 − 0.7×age was fitted on a different sample and is not “more official,” just another regression. This page shows both so you can see a few bpm of disagreement, not so you pick the higher number to justify intervals.

At age 30 with rest 60, Karvonen 50% is 125 and 60% is 138 on Fox 190. That 125–138 band is often closer to what people mean by easy aerobic work than 50–60% of 190 (95–114), which can sit near rest for a fit person and feel like a nap. The debate is definitional. Name your method when you log training. The default 133 versus 151 pair exists specifically to keep %HRmax and Karvonen from being used as synonyms.

Children should not be parked on 220 − age from a website; pediatric exercise testing is specialized. Very old adults can have conduction disease that makes HRmax meaningless as a training target. Pacemakers may cap rate. None of those cases is this form. Heat acclimation can raise pulse at a given pace without a change in Fox HRmax; the table will not know you arrived from a cold climate last week.

Copy/clear/fullscreen and the unique split-track class are for layout, not for clinical documentation. If you need an official test, you need a lab and a protocol, not 190 bpm printed in a browser. Medications such as beta blockers remain a hard stop on interpreting these zones as effort.

Age 25 Fox HRmax = 195; 70% = 136.5 ≈ 137. Rest 55, Karvonen 70% = 55 + 0.7 × 140 = 153. Age 35 Fox = 185; 70% = 129.5; Tanaka = 208 − 24.5 = 183.5. Age 45 Fox = 175; 70% = 122.5; rest 70, Karvonen 70% = 70 + 0.7 × 105 = 143.5. Age 55 Fox = 165; Tanaka = 208 − 38.5 = 169.5. Those rows are algebra. They are not a claim that a 55-year-old “should” interval at 90–100% of 165.

Resting HR of 40 in an endurance athlete with Fox 190 makes Karvonen 70% = 40 + 0.7 × 150 = 145, still above 70% HRmax (133) but less dramatic than rest 60 → 151. Rest 80 with the same Fox 190 makes Karvonen 70% = 80 + 0.7 × 110 = 157. High rest can be fitness-neutral (white coat, caffeine) or a reason to see a clinician. This form will not triage that.

Zone 90–100% of HRmax is near estimated maximum. Unsupervised all-out efforts are how people discover they needed a stress test yesterday. We print the band because the teaching grid has five rows, not because we want a sprint finish on a public road. Beta blockers, calcium-channel blockers that affect rate, and some psychotropic drugs still invalidate the story. Not a stress test. Not medical advice.

Default age 30, rest 60 → Fox 190; 70% HRmax = 133; Karvonen 70% = 151. Unique thr-split-track, 30-day storage, copy and clear. Optional Tanaka column for comparison only.