Health & Fitness · Free tool
Zone 2 Heart Rate Calculator
Find your optimal zone 2 cardio heart rate online using Karvonen, Maffetone, or max-HR methods. Based on longevity research — free calculator with instant results, no signup.
Updated June 2026
Zone 2 target heart rate
138 – 150 bpm
Max HR estimate: 189 bpm
How to use it
- Stay in this range for 30–90 min, 2–4×/week.
- Should feel easy: nasal breathing only, can hold a full conversation.
- Use heart-rate strap for accuracy (wrist optical undercounts during steady-state).
- Pace by HR, not by perceived effort — you’ll go too fast.
Zone 2 builds mitochondrial density and aerobic base. The 3 methods give slightly different ranges; Karvonen (which uses your resting HR) is most personalized; 180-minus-age is the conservative MAF method; %max is the classic textbook version. Pick one and stick with it.
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What it does
Calculate your Zone 2 cardio heart rate range with three methods: Karvonen (uses your resting HR for personalization), Maffetone (180 - age, conservative), or %max-HR (the textbook simple version). Zone 2 builds mitochondrial density and is the strongest correlate (with VO2 max) for all-cause mortality reduction. 30-90 min, 2-4×/week.
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Paste this snippet into any page. Loads on-demand (lazy), no tracking scripts, and sized to most dashboards. Replace the height to fit your layout.
<iframe src="https://freetoolarena.com/embed/zone-2-heart-rate-calculator" width="100%" height="720" frameborder="0" loading="lazy" title="Zone 2 Heart Rate Calculator" style="border:1px solid #e2e8f0;border-radius:12px;max-width:720px;"></iframe>How to use it
- Enter age + resting HR.
- Pick method.
- Stay in the range for 30-90 min, 2-4×/week.
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Show the math + sources
Formula
Karvonen: target HR = ((HRmax − HRrest) × intensity%) + HRrest. Maffetone (MAF): 180 − age, then ±5 / ±10 by health category.
What this assumes
HRmax estimated as 220 − age (±10–12 bpm error per Tanaka 2001). Not validated for users on beta blockers, with arrhythmias, or under 16 / over 65 (Maffetone explicitly excludes these). MAF adjustments are the author's clinical convention, not peer-reviewed.
Sources
Learn more
Guides about this topic
- How-To & Life · GuideWhy Zone 2 Cardio MattersZone 2 builds mitochondrial density, lowers BP/HbA1c, and is the strongest correlate (with VO2 max) for all-cause mortality reduction. How to do it right.
- How-To & Life · GuideHeart Rate Variability ExplainedAnalyze what HRV means, age-typical ranges, and factors that raise or lower it like sleep, zone 2, alcohol, and illness. Get your free analysis online in seconds.
- How-To & Life · GuideBeginner Marathon Training PlanRealistic 18-week first-marathon plan. Prerequisites, 4-phase structure, the 80/20 rule, race-week non-negotiables. Won't injure you if you start fit enough.
- How-To & Life · GuideOura vs Whoop vs Apple WatchThree categories of wearables in 2026: Oura (sleep + recovery), Whoop (athletes), Apple Watch / Garmin (everyday). Pick by what you'll actually look at.
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