# Zone 2 Heart Rate Calculator

> Free online tool that calculates your Zone 2 heart-rate training range using three honest methods side by side: the Tanaka % of max heart rate formula, the Karvonen heart-rate reserve formula, and the talk test. No signup. All calculation happens in the visitor's browser; nothing is uploaded or stored on a server.

## Calculator

- [Zone 2 Calculator](https://zone2calculator.com/): enter age (required), optional resting heart rate and measured max heart rate. Outputs the Zone 2 range by each method, all five heart-rate zones, and a weekly 150-minute training plan.
- [Zone 2 by Age](https://zone2calculator.com/zone-2-by-age/): estimated Zone 2 range for every age from 20 to 80, based on the Tanaka max heart rate formula. Population estimates, not a personal prescription.

## Methods

- Tanaka, Monahan & Seals (2001): max heart rate = 208 − 0.7 × age. Zone 2 = 60–70% of max heart rate. Population estimate; an individual's true max can differ by ±10–12 bpm.
- Karvonen, Kentala & Mustala (1957): target = resting HR + intensity × (max HR − resting HR). Zone 2 = 60–70% of the heart-rate reserve. More personal when resting heart rate is known.
- Talk test (field heuristic, not a formula): at Zone 2 you can speak in full sentences but could not sing.

## Training guidance

- At least 150 minutes of Zone 2 per week, in 3–5 sessions. Common templates: 3 × 50 minutes, 5 × 30 minutes, 4 × 45 minutes (180 minutes, above the minimum).
- Formula estimates are population averages. Medications that affect heart rate (e.g. beta blockers) make these formulas unreliable. This is educational content, not medical advice; people with a heart condition should consult a clinician before training by heart rate.

## About

- [Privacy, sources and methods](https://zone2calculator.com/about.html): privacy details (everything runs locally), formula citations, open-source credits, and the design references used on this site.

## Optional

- [Full text for AI systems](https://zone2calculator.com/llms-full.txt): the complete method detail and FAQ content of this site in one file.