How to Calculate a Delta Percentage

Method 1

• 1

  Calculate the percentage change using the equation [X(final) - X(initial)] / X(initial) * 100.

• 2

  Suppose the cargo space is 34.2 in the old model of a car and 32.6 cubic feet in the new model. Subtract the new value from the old value. 32.6 cubic feet - 34.2 cubic feet = -1.6 cubic feet.

• 3

  Divide by the old value: -1.6 cubic feet / 34.2 cubic feet = -0.0468.

• 4

  Convert to a percent: -0.0468 * 100 = -4.68 percent. The cargo space dropped by 4.68 percent.

Method 2

• 5

  Calculate the percentage change using the equation [X(final) / X(initial) * 100] - 100 percent.

• 6

  Use the same cargo space example of 34.2 in the old model of a car and 32.6 cubic feet in the new model. Divide the new value by the old value: 32.6 cubic feet / 34.2 cubic feet = 0.953.

• 7

  Convert to a percentage: 0.953 * 100 = 95.3 percent.

• 8

  Subtract 100 percent. 95.3 percent - 100 percent = -4.7 percent. The difference between Method 1 and Method 2 comes from the difference in rounding.