For words smaller than 25 cm, cm is calculated at the widest point. For example, if the length of a word is 12 cm and the height is 15 cm, then the word is 15 cm, and the unit price multiplied by the thickness is the price of the word.
For words larger than 25 cm, the calculated area, that is, the length multiplied by the height of the word, is the area of the word, and the unit price of the area multiplied by the thickness is the price of the word.