Heart Rate Zone Calculator
Training zones from your age and resting heart rate.
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Training by heart rate zones lets you target specific adaptations — recovery, endurance, tempo, or speed. This calculator gives you all five zones in beats per minute, using either the Karvonen method (which accounts for your resting heart rate) or a simple percentage of maximum.
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Heart Rate Zones — The Quick Answer
Estimate your maximum heart rate as 220 − age, then split it into zones from 50% to 100%. The Karvonen method is more personal: target HR = ((max − resting) × intensity) + resting.
Shortcut
Max HR ≈ 220 − age | Karvonen: ((Max − Rest) × %) + Rest
The five training zones
| Zone | Intensity | What it trains |
|---|---|---|
| 1 — Recovery | 50–60% | Warm-up, cool-down, recovery |
| 2 — Aerobic base | 60–70% | Endurance and fat-burning base |
| 3 — Tempo | 70–80% | Aerobic conditioning |
| 4 — Threshold | 80–90% | Lactate threshold, race pace |
| 5 — Maximum | 90–100% | Sprints and VO2 max intervals |
Most endurance training should sit in Zones 2 and 3, with only small amounts in Zones 4–5. A common split is roughly 80% easy and 20% hard.
How It Works
The Formulas
Two common methods
Formula
Max HR ≈ 220 − age Karvonen: Target = ((Max − Rest) × %) + Rest %-of-max: Target = Max × %
Variables
Maximum heart rate
The highest rate you can reach. 220 − age is a rough population estimate; an actual test is more accurate.
Resting heart rate
Your heart rate at complete rest, ideally measured on waking. Lower usually means better cardiovascular fitness.
Heart rate reserve
Max HR minus resting HR. The Karvonen method scales this reserve, personalising each zone.
Note: The Karvonen method is generally preferred because a fit person with a low resting heart rate gets zones pitched to their actual working range, not just their age.
Worked Example: Zone 2 for a 30-Year-Old
Karvonen method with a resting heart rate of 60 bpm
Estimate maximum heart rate
220 − 30 = 190 bpm
Find heart rate reserve (Karvonen)
190 − 60 (resting) = 130 bpm
Apply the zone's intensity range
Zone 2 = 60–70% → 0.60–0.70 × 130 = 78–91
Add resting heart rate back
78 + 60 to 91 + 60 = 138–151 bpm
Reference Guide
| Zone | % of max HR | What it builds | bpm (max 190) |
|---|---|---|---|
| 1 — Recovery | 50–60% | Warm-up, cool-down, recovery | 95–114 |
| 2 — Aerobic base | 60–70% | Endurance, fat-burning base | 114–133 |
| 3 — Tempo | 70–80% | Aerobic conditioning | 133–152 |
| 4 — Threshold | 80–90% | Lactate threshold, race pace | 152–171 |
| 5 — Maximum | 90–100% | Sprints, VO2 max intervals | 171–190 |
How to Train in Each Zone
What the zones are for — and the 80/20 rule
Comfortable, conversational effort. This is where endurance is built and where most athletes spend around 80% of their time. Zone 2 in particular develops your aerobic engine with low stress, so you can do a lot of it. If you can't hold a conversation, you're going too hard.
Best for: The bulk of weekly training volume
'Comfortably hard' to genuinely hard, sustainable only for limited stretches. Valuable in smaller doses for race-specific fitness, but easy to overuse — the classic trap is making every session a mediocre Zone 3 that's too hard to recover from and too easy to drive improvement.
Best for: A smaller, deliberate share of training
Near-maximal, for short intervals and sprints only. Powerful for raising your ceiling but demanding to recover from, so use it sparingly. Build an aerobic base first, and ease in if you're new to intense training.
Best for: Short, infrequent high-intensity intervals
220 − age can be off by 10–15 bpm for an individual, which shifts every zone. If Zone 2 feels impossibly easy or hard, your true maximum differs — a field or lab test gives better numbers. This is general fitness guidance, not medical advice.
Best for: Treating the zones as a starting point to refine
What Are Heart Rate Training Zones?
Heart rate zones are bands of exercise intensity, usually five, defined as percentages of your maximum heart rate or heart rate reserve. Each zone develops a different aspect of fitness — easy Zone 1–2 work builds the aerobic base and burns fat, while hard Zone 4–5 efforts raise your threshold and top-end power. Training by zones means pitching each session at a deliberate intensity instead of guessing, which is why heart rate cuts through how pace alone can mislead on tired or hot days. This calculator gives all five zones using either the Karvonen method (which personalises them to your resting heart rate) or a simple percentage of maximum.
Key Features
💡 Pro Tips
- →Aim for roughly 80% of your training in the easy zones (1–2) and 20% hard (4–5) — the polarised split most endurance athletes use.
- →Measure resting heart rate on waking, before coffee, for the most accurate Karvonen zones.
- →If your easy runs keep drifting into Zone 3, deliberately slow down — 'easy' should feel almost too easy to be a workout.
- →A chest-strap monitor tracks fast intensity changes more accurately than a wrist optical sensor, which can lag during intervals.
Common Mistakes
Training everything at a mediocre middle intensity
The most common error: easy days too hard, hard days too easy. Everything blurs into Zone 3, which is too taxing to recover from yet too gentle to drive big gains. Keep easy easy so you can make hard genuinely hard.
Trusting 220 − age as your exact maximum
It's a population average that can be off by 10–15 bpm. If your zones feel wrong, your true max differs, and every zone shifts with it. Use a tested max HR where possible.
Chasing the 'fat-burning zone' for weight loss
Lower intensities burn a higher proportion of fat, but higher intensities burn more total calories. For fat loss, overall energy balance matters far more than training in one specific zone.
Research & Citations
Sources and standards referenced for the factual claims on this page
- [1]
Karvonen, M. J., Kentala, E., & Mustala, O. (1957). The effects of training on heart rate: a longitudinal study. Annales Medicinae Experimentalis et Biologiae Fenniae, 35(3).
Origin of the heart rate reserve (Karvonen) method.
View source - [2]
American College of Sports Medicine (ACSM) (2021). ACSM's Guidelines for Exercise Testing and Prescription (11th ed.). Wolters Kluwer.
Standard reference for exercise intensity and heart rate zones.
View source - [3]
Seiler, S. (2010). What is best practice for training intensity and duration distribution in endurance athletes?. International Journal of Sports Physiology and Performance, 5(3).
Research behind the polarised (roughly 80/20) training distribution.
View source
This calculator is a reference tool, not a substitute for professional advice. Verify important health, financial, legal, or safety decisions with a suitably qualified professional.
Last updated: October 7, 2026
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Frequently Asked Questions
How do I calculate my heart rate zones?
Estimate your maximum heart rate (220 − age), then apply percentages. For the Karvonen method, subtract your resting rate, multiply the result by the zone's percentage, then add the resting rate back. This calculator does both methods for you.
What is the Karvonen formula?
Target heart rate = ((Max HR − Resting HR) × intensity %) + Resting HR. It uses your heart rate reserve so the zones reflect your personal fitness rather than just your age.
Which heart rate zone burns the most fat?
Zone 2 (about 60–70% of maximum) burns the highest proportion of fat, though higher zones burn more total calories. For overall fitness it's best to train across zones, not just one.
Is 220 minus age accurate?
It's a rough population average and can be off by 10–15 bpm for an individual. A field test or lab test gives a much better figure — if you know your true maximum, enter it directly.