Considering the above map, the steps involved in contour interval calculation are, Let’s assume, 7000 and 7100 and calculate the interval between it. Now difference between 7100 and 7000 is 7100 - 7000 = 100 The number of contour lines in-between 7000 and 7100 are 4. Adding 1 to 4, 4 + 1 = 5 Now dividing 100 by 5, 100/5 = 20 units The Contour Interval of the above map us 20 Units.
