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Heart Rate Zone Calculator
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Heart Rate Zone Calculator

Calculate target heart rate zones for fat burn, cardio, and peak performance. Free heart rate zone calculator with Karvonen formula.

Works Offline100% Free

Processed 100% locally in your browserPrivate & Safe

Heart Rate Zone Calculator runs entirely on your device using Web API standards. No data is ever uploaded to UtilixVerse servers.

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No Server UploadsNo Account RequiredWorks OfflineZero Data Logging
Your Heart Rate Profile
Max Heart Rate Formula
Meta-analysis (2001) — best general estimate
bpm
Measure it first thing in the morning, before getting out of bed, on 3 consecutive days and take the average.
Zone Method
Zones as a straight percentage of max heart rate — simple and common.
Your Zones
Tanaka
Estimated Max Heart Rate
187bpm
Tanaka · 208 − 0.7 × age
AHA Moderate
94–131 bpm
50–70% of max
AHA Vigorous
131–159 bpm
70–85% of max
1
Recovery50–60% max HR
Very light — easy warm-up, rhythmic breathing · Active recovery, stress reduction, base fitness
94–112bpm
2
Fat Burn60–70% max HR
Comfortable — full conversation possible · Aerobic base, fat oxidation, mitochondrial density
112–131bpm
3
Cardio70–80% max HR
Moderate — conversation becomes difficult · Aerobic capacity, lactate clearing, heart efficiency
131–150bpm
4
Threshold80–90% max HR
Hard — forceful breathing, uncomfortable · Anaerobic threshold, speed endurance
150–168bpm
5
Maximum90–100% max HR
Very hard — sprinting, unsustainable · VO₂ max, max power, neuromuscular speed
168–187bpm
Percent-of-max zones are the standard model used by most wearables. Age-predicted formulas have a ±10–20 bpm margin of error — for precise zones, use a measured max HR from a lab test.
Printable Zone Chart
Heart Rate Training ZonesMax HR 187 bpm · Tanaka · % of max HRAHA vigorous ≥ 70%Z1 · Recovery94–112 bpmZ2 · Fat Burn112–131 bpmZ3 · Cardio131–150 bpmZ4 · Threshold150–168 bpmZ5 · Maximum168–187 bpm94112131150168187bpmAHA health guidelines: moderate 94–131 bpm · vigorous 131–159 bpmAge-predicted max HR carries a ±10–20 bpm margin of error — verify with a measured max HR for precise training zones.
History is stored locally in your browser.
History0
No saved calculations yet. Hit “Save to History” to keep a local log of your heart rate zones.

Free Heart Rate Zone Calculator — Train Smarter

Welcome to the UtilixVerse heart rate zone calculator. Whether you arerunning, cycling, lifting, or just starting anexercise program, this free tool turns your age into personalizedtarget heart rate zones using evidence-based formulas. No sign-up, no uploads, and everything runs in your browser.

How Our Heart Rate Calculator Works

The calculator estimates your maximum heart rate from your age using a formula you choose — the classic 220 − age, the Tanaka (208 − 0.7 × age),Gulati for women (206 − 0.88 × age), or Nes et al. (211 − 0.64 × age) — or you can enter a measured max HR. It then maps the standard5 training zones onto that number, and optionally applies theKarvonen Heart Rate Reserve method using your resting heart rate for targets that reflect your fitness level.

The 5 Training Zones at a Glance

Zone 1 — Recovery50–60% max HR
Zone 2 — Fat Burn / Aerobic Base60–70% max HR
Zone 3 — Cardio / Tempo70–80% max HR
Zone 4 — Threshold80–90% max HR
Zone 5 — Maximum / VO₂ max90–100% max HR

% Max HR vs. Karvonen Heart Rate Reserve

Percent-of-max zones are simple — each zone is a fixed slice of your maximum heart rate. The Karvonen method uses your heart rate reserve (max minus resting HR) instead:target = (HRmax − HRrest) × % + HRrest. Because it accounts for how fit your resting heart rate is, Karvonen targets are more personal — a well-trained athlete with a 45 bpm resting HR gets meaningfully different zones than a sedentary person with 75 bpm.

AHA Intensity Ranges

The American Heart Association recommends moderate-intensity exercise at50–70% of max HR and vigorous-intensity exercise at70–85% of max HR, aiming for at least 150 minutes of moderate (or 75 minutes of vigorous) activity per week. The calculator shows these ranges alongside your zones so you can match them to general health guidelines.

Tips for Accurate Heart Rate Zones

  1. 1. Measure your resting heart rate first thing in the morning, before getting up, for 3 days, and average the readings.
  2. 2. Age-based formulas carry ±10–20 bpm of error — for precision, use a measured max HR from a lab test or a max-effort workout.
  3. 3. Use a chest-strap monitor for the most accurate bpm during training; wrist optical sensors lag during intervals.
  4. 4. Re-calculate your zones as your fitness improves — your resting HR will likely drop, shifting Karvonen targets.

Your data never leaves your device — this is a 100% private, free heart rate calculatorfor running, cycling, and all your training zones.

Medical Disclaimer: This heart rate calculator provides estimates for informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Consult your doctor before starting a new exercise program, especially if you have a heart condition or are over 40 and previously inactive.

Last medically reviewed: July 31, 2026 | Reviewed by: Medical Review Board

Frequently Asked Questions About Heart Rate Zones

What is my maximum heart rate?

Your maximum heart rate (HRmax) is the highest number of beats per minute your heart can reach during all-out exercise. The classic estimate is 220 minus your age, while the Tanaka formula (208 − 0.7 × age) is more accurate for the general population and the Gulati formula (206 − 0.88 × age) is validated specifically for women. Our calculator lets you pick the formula, or enter a measured max HR from a lab test for the most precise zones.

What are the 5 heart rate zones?

The standard model divides max heart rate into five zones: Zone 1 Recovery (50–60%), Zone 2 Fat Burn / aerobic base (60–70%), Zone 3 Cardio / tempo (70–80%), Zone 4 Threshold (80–90%), and Zone 5 Maximum / VO₂ max (90–100%). Each zone trains a different energy system — from active recovery and fat oxidation at the low end to anaerobic capacity at the top.

What is the difference between % max HR and the Karvonen method?

Percent-of-max zones are a straight percentage of your maximum heart rate. The Karvonen Heart Rate Reserve (HRR) method instead uses the gap between your max and resting heart rate: target HR = (HRmax − HRrest) × % intensity + HRrest. Because it accounts for your resting HR, Karvonen targets are more personalised — two people with the same max HR but different resting HRs get different zones.

Which heart rate formula is most accurate?

The Tanaka formula (208 − 0.7 × age) is often recommended for the general population because it was derived from a large meta-analysis. The Gulati formula (206 − 0.88 × age) is validated for women, and Nes et al. (211 − 0.64 × age) came from a large fitness study. That said, all age-based formulas carry roughly ±10–20 bpm of error — a directly measured max HR from a graded exercise test is the gold standard.

What heart rate zone should I train in to burn fat?

Zone 2 (60–70% of max HR) is often called the fat-burn zone because your body relies most heavily on fat for fuel at that intensity. However, total calorie burn matters more than the percentage of fat used — higher zones burn more total calories. A well-rounded programme includes Zone 2 base work, Zone 3–4 intervals for fitness, and Zone 5 efforts for top-end power.

What zone improves my VO₂ max and endurance?

Zone 5 (90–100% of max HR) develops VO₂ max and anaerobic power, while Zone 3–4 (70–90%) builds aerobic capacity and raises your lactate threshold. For endurance athletes, most weekly volume should sit in Zone 2 with a smaller share of hard Zone 4–5 sessions — the classic 80/20 approach used by many coaches.

Is the 220 minus age formula accurate?

220 minus age is the classic quick estimate, but research shows it tends to overestimate max HR in younger people and underestimate it in older adults, with up to ±10–20 bpm of individual error. The Tanaka formula (208 − 0.7 × age) is generally more accurate, and a measured max HR is best for precise training zones.

Is this heart rate calculator free and private?

Yes. The calculator is 100% free with no registration, and every calculation runs entirely in your browser — no data is ever sent to a server. If you choose to save results, they are stored only in your browser's localStorage, and you can export, import, or clear your history at any time.

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