Determine the difference in elevation in absolute terms by subtracting the lower, or first elevation from the higher, or second elevation. Say, for example, a biker starts at an elevation of 8,000 feet and climbs to 11,000 feet. That equation would be 11,000 feet minus 8,000 feet equals 3,000 feet.
Divide the difference by the original elevation to arrive at the percentage of increase expressed as a decimal. In this example, 3,000 divided by 8,000 equals 0.375.
Multiply by 100 to arrive at the answer expressed in percentage points. In this example, 0.375 times 100 equals 37.5, or an elevation increase of 37.5 percent.