You can hover over places on the chart to get exact values. In January 1980, the index was at 37.124. In April 2025, it was at 125.880.

Then calculate cumulative inflation as the proportional change in the price level, like this:

(P_final - P_initial) / P_initial = (125.880 - 37.124) / 37.124 = 2.39

This shows that the overall price level (the cumulative inflation embodied in the PCEPI) has increased by about 2.39 times over the period, which is 239%.

The thing that bugs me to no end when talking about inflation in an historical context, is that everyone forgets to consider how the indexes of consumption it's calculated from (PCEPI, CPI, etc.) are NOT static, and very arbitrarily are changed over time, often to make inflation seem lower than it actually is for the consumer.

Overall, historical comparisons of inflation numbers are so imprecise to be practically worthless the longer the timescale. You can expect the real figure to be much greater in reality for consumers, given the political incentive to lie over inflation data.

1.0275 ^ 45 = 3.389

3.389 - 1 (to account for increase) = 2.38 ~ 239%