Heart Rate Zone Calculator
Find your five heart rate training zones. Enter your age for the standard estimate — add your resting heart rate for the more personal Karvonen calculation used by coaches.
How to use this calculator
- Enter your age — this estimates your maximum heart rate.
- Optionally add your resting heart rate (measured on waking) for personalized Karvonen zones.
- Train by zone: most easy runs belong in Zone 2, intervals in Zone 4–5.
Formula used
The Karvonen method scales percentages over your heart rate reserve (max minus resting) rather than raw max, which fits trained individuals better — a lower resting HR shifts every zone. Tanaka's 208 − 0.7×age tracks real data better past age 40.
Example calculation
Age 30: max ≈ 190 bpm, so Zone 2 (easy) = 114–133 bpm by the simple method.
With resting HR 60, Karvonen gives Zone 2 = (130 × 0.6–0.7) + 60 = 138–151 bpm — notably higher, which is why fit people using the simple method often train too easy.
Training by heart rate zones
Zones map effort to physiology: Zone 2 builds the aerobic base and burns the highest fat fraction, Zone 4 pushes your lactate threshold, Zone 5 develops VO2 max in short bursts. The classic endurance mistake is living in Zone 3 — too hard to recover from daily, too easy to force adaptation — which zone-aware training fixes with the 80/20 pattern: mostly easy, occasionally very hard.
All formulas estimate a population average; your true max can differ by ±10 bpm. Perceived effort and the talk test (full sentences = Zone 2) are honest cross-checks.
Why use this calculator?
- Keep easy days genuinely easy — the core of effective endurance training.
- Get personalized zones via Karvonen when you know your resting HR.
- Set watch/chest-strap zone alerts with real numbers.
Frequently asked questions
What heart rate burns the most fat?
Zone 2 (60–70%) burns the highest percentage of calories from fat, but higher zones burn more total calories — and total energy balance decides fat loss. Zone 2's real virtue is building an aerobic base you can train daily.
Is 220 minus age accurate?
It's a rough population average with ±10–12 bpm of individual spread, and it underestimates for older adults — Tanaka's 208 − 0.7×age fits better past 40. A field max test or lab test beats any formula.
Why do my watch's zones differ from these?
Devices use different max-HR formulas, sometimes a measured max, and either %max or Karvonen scaling. Set your watch's max HR (and resting HR) to your real values and the zones converge.