To convert 12 inches to centimeters, you will need to use the conversion factor that 1 inch is equal to 2.54 centimeters. This means that for every inch, there are 2.54 centimeters.

Step 1: Write down the given value: 12 inches.

Step 2: Set up the conversion factor as a fraction, with inches on the bottom and centimeters on the top. It will look like this: 2.54 cm/1 inch.

Step 3: Multiply the given value (12 inches) by the conversion factor fraction. This will cancel out the inches unit and leave you with the equivalent value in centimeters. The calculation will look like this: 12 inches x (2.54 cm/1 inch).

Step 4: Solve the equation using simple multiplication. 12 x 2.54 = 30.48 centimeters.

Step 5: Label the final answer with the appropriate unit. In this case, it is 30.48 centimeters.

Therefore, 12 inches is equal to 30.48 centimeters. You can use this same method for any conversion between inches and centimeters, just make sure to adjust the conversion factor accordingly.