Question: 12 inch means how many cm?
Answer: And the conversion for the inch to the centimeter is 1 inch = 2.54 cm exactly. So, in the same vCalc conversion equation (Length Conversion), if you input 1 inch, you get out 2.54 cm. So, he rephrased answer to your question is: there are 30.48 centimeters on a standard 12 inch ruler.