ECG Rate Calculator
Enter ECG paper measurements to calculate heart rate using the RR interval or 1500 method at 25 or 50 mm/s paper speeds.
ECG Measurements
Enter the RR interval in milliseconds (e.g. 750 ms = 80 bpm).
Enter values on the left and click Calculate.
Heart Rate
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bpm
Method
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Paper Speed
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Input Used
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RR Interval
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Quick Reference
| Classification | Rate (bpm) | RR at 25 mm/s (ms) |
|---|---|---|
| Bradycardia | < 60 | > 1000 ms |
| Normal Sinus | 60 – 100 | 600 – 1000 ms |
| Tachycardia | > 100 | < 600 ms |
Disclaimer: This tool is for educational purposes only. Do not use it as a substitute for clinical assessment or professional medical advice.
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Summary
Enter ECG paper measurements to calculate heart rate using the RR interval or 1500 method at 25 or 50 mm/s paper speeds.
How it works
- Select the paper speed used on the ECG recording: 25 mm/s (standard) or 50 mm/s (used in some countries and stress tests).
- Choose a calculation method: RR Interval (enter the time between two R waves in milliseconds) or 1500 Method (count the small squares between two consecutive R peaks).
- Enter the measured value and click Calculate.
- The tool divides the method constant by your input to produce the heart rate in beats per minute.
- Use the rate interpretation guide to see where the result falls (bradycardia, normal sinus, tachycardia).
- For irregular rhythms, measure multiple RR intervals and use the average — the tool supports averaging up to 6 intervals.
Use cases
- Medical and nursing students learning ECG interpretation.
- Paramedics and EMTs verifying rhythm rates in the field.
- Educators preparing ECG teaching materials.
- Self-study and exam preparation for clinical certifications.
- Cross-checking manual ECG caliper measurements.
- Converting between mm small-square counts and BPM quickly.
Frequently Asked Questions
Last updated: 2026-06-10 ·
Reviewed by Nham Vu