How the inflation calculator works

(CPI= consumer price index or price index)

In today's prices

For example, imagine you want to know what goods and services costing KES 23 in 1975 would have cost in 2023:

The price index for 1975 = 17.78

The price index for 2023 = 44.6

The calculator increases the cost in 1975 by the change in prices between 1975 and 2023 with this formula:

𝐶𝑜𝑠𝑡 𝑖𝑛 2023 = 𝐶𝑜𝑠𝑡 𝑖𝑛 1975 × 2023 𝑝𝑟𝑖𝑐𝑒 𝑖𝑛𝑑𝑒𝑥 1975 𝑝𝑟𝑖𝑐𝑒 𝑖𝑛𝑑𝑒𝑥

𝐾𝐸𝑆 57. 68 = 𝐾𝐸𝑆 23 × 44.6 17.78

So the cost in 2023 of the same goods and services has risen to KES 57.68.

Alternatively in yesterday’s prices

For example, imagine you want to know what goods and services costing KES 57.68 in 2023 would have cost in 1975:

The price index for 2023 = 44.6

The price index for 1975 = 17.78

The calculator decreases the cost in 2023 by the change in prices between 2023 and 1975 with this formula:

𝐶𝑜𝑠𝑡 𝑖𝑛 1975 = 𝐶𝑜𝑠𝑡 𝑖𝑛 2023 × 1975 𝑝𝑟𝑖𝑐𝑒 𝑖𝑛𝑑𝑒𝑥 2023 𝑝𝑟𝑖𝑐𝑒 𝑖𝑛𝑑𝑒𝑥

𝐾𝐸𝑆 22. 9944 = 𝐾𝐸𝑆 57. 68 × 17.78 44.6

So the cost in 1975 of the same goods and services would have been KES 22.9944. 

The Kenya Inflation rate calculator is available here Yuthufu.com