Image processing has been significantly transformed in recent years by technological advances that provide solutions that are exceptionally efficient and demand few resources. Utilizing 2D images exclusively eliminates the necessity for expensive and occasionally unattainable scanning technologies such as 3D or 2D scanners, thereby facilitating the development of rapid measurement systems. Using cameras and image processing technology, this article describes an automated technique for determining the size of fingers. After generating a binary image and extracting finger contours via OpenCV image processing and camera calibration, the procedure proceeds to calculate actual sizes via a sampling technique. Comparing hand data from several subjects to manual measurements taken with a ruler, the OpenCV library-implemented Python system was evaluated. The findings highlight the effectiveness of the system, which completes ring size measurements in the jewelry and customer service sectors in a mere 0.5 s, as opposed to the manual method’s mean of 11 s.