Target Heart Rate Zones Calculator
This calculator computes target heart rate zones using multiple accepted methods: age-based estimates (Tanaka and 220 − age), user-measured maximum heart rate, and the Karvonen heart rate reserve method. Use the method most appropriate to your situation and provide measured values when available for greater accuracy.
Results are presented as beats per minute ranges for common training zones. The tool includes accuracy guidance and recommended best practices for device calibration and data quality.
Governance
Record f3d4db1630ef • Reviewed by Fidamen Standards Committee
Applies the Karvonen formula (target = resting + % * (max − resting)) where max is estimated by the Tanaka formula.
Inputs
Results
Heart Rate Reserve (HRR)
BPM 127.00
Zone 1 lower (50% HRR)
BPM 123.50
Zone 1 upper (60% HRR)
BPM 136.20
Zone 2 lower (60% HRR)
BPM 136.20
Zone 2 upper (70% HRR)
BPM 148.90
Zone 3 lower (70% HRR)
BPM 148.90
Zone 3 upper (80% HRR)
BPM 161.60
Zone 4 lower (80% HRR)
BPM 161.60
Zone 4 upper (90% HRR)
BPM 174.30
Zone 5 lower (90% HRR)
BPM 174.30
Zone 5 upper (100% HRR)
BPM 187.00
| Output | Value | Unit |
|---|---|---|
| Heart Rate Reserve (HRR) | BPM 127.00 | bpm |
| Zone 1 lower (50% HRR) | BPM 123.50 | bpm |
| Zone 1 upper (60% HRR) | BPM 136.20 | bpm |
| Zone 2 lower (60% HRR) | BPM 136.20 | bpm |
| Zone 2 upper (70% HRR) | BPM 148.90 | bpm |
| Zone 3 lower (70% HRR) | BPM 148.90 | bpm |
| Zone 3 upper (80% HRR) | BPM 161.60 | bpm |
| Zone 4 lower (80% HRR) | BPM 161.60 | bpm |
| Zone 4 upper (90% HRR) | BPM 174.30 | bpm |
| Zone 5 lower (90% HRR) | BPM 174.30 | bpm |
| Zone 5 upper (100% HRR) | BPM 187.00 | bpm |
Visualization
Methodology
Three approaches are provided so users can choose the most appropriate method: (1) Age-based estimates produce a quick estimate of maximum heart rate; (2) Measured maximum heart rate accepts user-supplied values from validated maximal tests or calibrated devices; (3) Karvonen (heart rate reserve) adjusts target intensities by resting heart rate to individualize ranges.
For device and data quality recommendations we follow general guidance from standards bodies for health device interoperability and quality management, including IEEE 11073 for personal health device communication, ISO 13485 for medical device quality systems when applicable, and NIST recommendations for measurement and data integrity. Users should ensure wearable devices are worn and paired correctly and that maximal heart rate measurements were collected under supervised or validated protocols.
Worked examples
Example 1: 30 years old, resting HR 60 bpm, method Karvonen (Tanaka): Tanaka max HR = 208 − 0.7×30 = 187 bpm. HRR = 187 − 60 = 127 bpm. Zone 2 (60–70% HRR) = 60 + 0.60×127 to 60 + 0.70×127 → 136 to 148 bpm.
Example 2: Measured max 190 bpm, resting HR 55 bpm, % of max zones: Zone 3 (70–80% of max) = 0.70×190 to 0.80×190 → 133 to 152 bpm.
F.A.Q.
Which method is most accurate?
A measured maximum heart rate obtained from a validated maximal effort test or calibrated device is the most accurate basis for zone calculations. Karvonen (HRR) further individualizes zones by using resting heart rate. Age-based formulas provide quick estimates but have population-level error and do not account for individual variation.
What if I do not know my resting heart rate?
For Karvonen calculations you need resting heart rate. Measure it after waking and while still lying down, or use a 60-second average from a reliable wearable. If unknown, use the percentage-of-max methods instead but expect less personalization.
Are these results a substitute for medical advice?
No. This calculator provides informational estimates only. Consult a healthcare professional before beginning or changing an exercise program, particularly if you have cardiovascular disease, are on medication, or have other health concerns.
How accurate are age-based formulas?
Age-based formulas (e.g., Tanaka or 220 − age) have typical standard errors that can be large for individuals. Use them only when measured data is unavailable and treat results as approximate.
How should I calibrate my wearable?
Follow the device manufacturer's guidance for fit and firmware updates. When possible, validate wearable readings during resting and known-intensity activities. Refer to device-specific calibration and IEEE 11073 interoperability recommendations for data integrity practices.
Sources & citations
- IEEE 11073 Personal Health Device Standards — https://standards.ieee.org/standard/11073-10406-2019.html
- ISO 13485 Medical devices — Quality management systems — https://www.iso.org/standard/59752.html
- NIST - Guidance on Measurement, Data Integrity and Device Security — https://www.nist.gov
- Occupational Safety and Health Administration (OSHA) — Medical and workplace guidance — https://www.osha.gov
- ACSM — Target Heart Rate Recommendations — https://www.acsm.org/
- American Heart Association — Target Heart Rates — https://www.heart.org/en/healthy-living/fitness/fitness-basics/target-heart-rates
Further resources
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
Record ID: f3d4db1630efWhat changed (latest)
v1.0.0 • 2025-11-03 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Public QA status
PASS — golden 25 + edge 120
Last run: 2026-01-23 • Run: golden-edge-2026-01-23
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
What changed (latest)
v1.0.0 • 2025-11-03 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Public QA status
PASS — golden 25 + edge 120
Last run: 2026-01-23 • Run: golden-edge-2026-01-23
Engine
v1.0.0
Data
Baseline (no external datasets)
Content
v1.0.0
UI
v1.0.0
Governance
Last updated: Nov 3, 2025
Reviewed by: Fidamen Standards Committee (Review board)
Credentials: Internal QA
Risk level: low
Reviewer profile (entity)
Fidamen Standards Committee
Review board
Internal QA
Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person
Semantic versioning
- MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
- MINOR: New features or fields that do not change existing outputs for the same inputs.
- PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.
Review protocol
- Verify formulas and unit definitions against primary standards or datasets.
- Run golden-case regression suite and edge-case suite.
- Record reviewer sign-off with credentials and scope.
- Document assumptions, limitations, and jurisdiction applicability.
Assumptions & limitations
- Uses exact unit definitions from the Fidamen conversion library.
- Internal calculations use double precision; display rounding follows the unit's configured decimal places.
- Not a substitute for calibrated instruments in regulated contexts.
- Jurisdiction-specific rules may require official guidance.
Change log
v1.0.0 • 2025-11-03 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: ac65dfb169fe