Ready Reference Files

Consumer Price Index (CPI), Calculating Percent Change

Important: for your calculation to be accurate, both CPI figures must have the same base year.

Step 1--Calculate the index point change.

Subtract the lower (usually older) CPI figure from the higher (usually later) CPI figure. The result is the index point change.

Example of Step 1--Index Point Change

Higher CPI figure:	189.8
Minus lower CPI figure:	-189.2
Equals index point change:	= 0.6

---

Step 2--Calculate Percent Change:

Divide the index point change by the lower CPI figure. Multiply the result by 100 for the percent change.

Example of Step 2--Percent Change

Index point change:	0.6
Divided by the lower CPI figure:	÷189.2
Equals:	= 0.003
Multiply by 100:	0.003 × 100
Equals percent change:	= 0.3%

---

No source given; Verified by: CM, 12/00

Disclaimer:
While the Library has verified the information presented in these files in what it considers to be reliable and authoritative sources, it cannot take responsibility for nor guarantee the accuracy of the information presented.