To convert miles to kilometers, you can use the conversion factor that 1 mile is equal to 1.60934 kilometers. Here are the step-by-step instructions to convert 18 miles to kilometers:

Step 1: Write down the given value.

18 miles

Step 2: Write down the conversion factor.

1 mile = 1.60934 kilometers

Step 3: Set up the conversion equation.

18 miles * (1.60934 kilometers / 1 mile)

Step 4: Cancel out the units.

miles in the numerator and denominator cancel out, leaving only kilometers.

Step 5: Perform the calculation.

18 * 1.60934 = 29.03412 kilometers

Step 6: Round the answer to an appropriate number of decimal places.

Since kilometers are typically rounded to two decimal places, the final answer is:

18 miles is approximately equal to 29.03 kilometers.

Therefore, 18 miles is approximately equal to 29.03 kilometers.