| What it does | Free Karvonen formula heart rate zone calculator
| Free random name picker powered by cryptographic randomness
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| Stage | Established
| Startup
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| Founded | Not given
| 2026
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| Based in | Not given
| Not given
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| Pricing model | Free
| Free
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| Pricing | Not given
| Free forever with no paywalls or hidden fees.
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| Key features | - Five personalized training zones based on heart rate reserve
- Accounts for resting heart rate and cardiovascular fitness
- Custom maximum heart rate input from multiple formulas
- No signup required, runs entirely in browser
- Weekly resting heart rate logging and progress tracking
- Zone-specific training guidance for different goals
- Shareable and printable zone results
- Embeddable calculator widget for websites
| - Cryptographically secure randomness using crypto.getRandomValues()
- Equal probability for all entries
- Remove and spin again functionality
- Recent Winners log tracking all decisions
- Built-in fairness test with 10,000 simulated spins
- No account or download required
- Works on any modern browser
- Client-side application with no data transmission
- Unlimited entries with auto-resizing segments
- Multiple wheel configurations for different use cases
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| What makes it different | - More accurate than age-only formulas, accounting for individual cardiovascular fitness
- Zones adapt as your fitness improves and resting heart rate drops
- Based on 1957 Karvonen research used by coaches and sports scientists
- Independent, no data collection or external servers
- No ads inside the calculator, free to use with optional embedding
| - Uses cryptographic randomness instead of predictable algorithms like Math.random()
- Built-in fairness verification test that runs 10,000 spins to prove equal distribution
- Completely private with no data stored on servers or shared with third parties
- Instant results with no signup, download, or hidden costs
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| Community votes | 0 | 0 |
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| DR (Domain Rating by Ahrefs) | 11 ● no change since last check | 4 ● no change since last check |
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| Trust Flow (Majestic) | 19 | 0 |
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| Citation Flow (Majestic) | 25 | 14 |
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| Referring domains (Majestic) | 40 | 3 |
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CalculateMyHeartRate
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