How to change inches to meters ？

Question

Here's the code, how to change inches to meters ？

box = cv2.boxPoints(marker)
cv2.drawContours(image, [box.astype(int)], -1, (0, 255, 0), 2)
cv2.putText(image, "%.2fft" % (inches / 12),
    (image.shape[1] - 200, image.shape[0] - 20), cv2.FONT_HERSHEY_SIMPLEX,
    2.0, (0, 255, 0), 3)
cv2.imshow("image", image)
cv2.waitKey(0)