Nursing guide
Exam-focused context for this calculator. For clinical care, follow orders, policies, and local protocols.
The ECG heart rate calculator estimates rate with the 300 method, 1500 method, 6-second strip method, and R-R interval method, and includes a basic rhythm checklist. It is an educational tool and does not diagnose rhythms.
ECG interpretation in real clinical care requires full patient assessment and qualified clinical review. Use this to build recognition, not to make care decisions.
300 method: HR = 300 ÷ large boxes between R waves (regular rhythms). 1500 method: HR = 1500 ÷ small boxes between R waves (regular, more precise). 6-second method: HR = QRS complexes in 6 seconds × 10 (works for irregular rhythms). R-R interval: HR = 60 ÷ R-R interval in seconds.
There are 4 large boxes between two R waves on a regular strip.
For a regular rhythm, divide 300 by the number of large boxes between two R waves. For example, 300 ÷ 4 large boxes = 75 bpm.
Use it for irregular rhythms. Count the QRS complexes in a 6-second strip and multiply by 10.
The 300 method uses large boxes for a quick estimate, while the 1500 method divides 1500 by the number of small boxes for a more precise rate on regular rhythms.
A common adult resting range is about 60 to 100 bpm, but any rate must be interpreted with the patient's stability and clinical picture.
No. It estimates rate and offers a rhythm checklist for study. Real ECG interpretation requires full patient assessment and qualified clinical review.
These answers are for nursing education and exam practice only and do not provide patient-specific medical advice.
When to use: Best for a regular rhythm; quick bedside estimate.
Rhythm checklist
Safety
Educational use only. ECG interpretation in real clinical care requires full patient assessment and qualified clinical review. This tool does not diagnose rhythms.
Want more practice?