ECG Boxes to Seconds Calculator

Convert ECG box measurements to time intervals in seconds. Calculate time from ECG grid measurements. This is an educational tool only - always consult a healthcare provider.

ECG Measurement

1 small box = 0.04 seconds at standard speed (25 mm/s)

Results

Enter ECG box measurement to calculate time

About ECG Boxes

  • • 1 small box = 0.04 seconds (25 mm/s)
  • • 1 large box = 0.20 seconds (5 small boxes)
  • • Standard speed: 25 mm/s
  • • Fast speed: 50 mm/s (half the time)