ECG Heart Rate Calculator
Estimate heart rate from an ECG strip based on the number of large or small grid boxes between R-waves.
Input Parameters
Enter details for calculation.
Estimated Heart Rate
Expert Tip
The 300 Rule divides 300 by the number of large boxes between R-R peaks. For irregular rhythms, count QRS complexes in a 6-second strip and multiply by 10.
Calculation Methodology & Details
Formula
Based on standard ECG paper speed of 25 mm/s where one large box represents 0.2 seconds.
Important Disclaimer
The calculations provided are for educational and general informational purposes only. They do not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider.
How ECG Heart Rate is Estimated
Follow these steps to use this calculator:
Count R-R Interval
Count grid squares between two consecutive R-wave peaks.
Calculate Rate
Use box count to find beats per minute.
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ℹ️ About this Calculation
This clinical cardiovascular calculator provides precise hemodynamics assessment, ischemic heart disease risk stratification, electrophysiology calculations, and vascular disease evaluation based on ACC/AHA guidelines.
Variable Glossary
Vascular & ECG Data
Systolic/diastolic blood pressure, pulse rate, ECG intervals (QT/RR), or ankle-brachial Doppler pressures.
Hemodynamic Scores
Mean arterial pressure (MAP), corrected QTc interval, ASCVD 10-year risk percentage, or ejection fraction.
How to Calculate Step-by-Step
Step 1
Input hemodynamic vitals, lab values, or ECG measurement parameters.
Step 2
Select patient demographics, clinical comorbidities, or exercise test responses.
Step 3
Review calculated risk scores, hemodynamic parameters, and clinical classification recommendations.