The Fibonacci sequence is a mathematical sequence in which each number is the sum of the two preceding ones. It begins with two 1s as such: 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, and so on. The difference between two adjacent numbers in the sequence provides a good estimation of the relationship between miles and kilometers and this becomes a better estimate as the sequence progresses. To use this to estimate the conversion of Kilometers to Miles, choose a number in the sequence such as 21 for kilometers. The preceding value in the sequence is the approximate equivelent in miles, 13. This works as the closed-form factor of the sequence is 1.61803 which is very close to the conversion factor of Miles to Kilometers which is 1.60934.