Future cost versus present purchasing power: why inflation gives two answers
One calculation asks how much money a future purchase may require. The other asks what a fixed future amount is worth in today’s purchasing power. Their directions are opposite.
Inflation calculator →State the question before calculating
To estimate the future cost of today’s basket, multiply its current amount by the assumed price-growth factor. To express a future fixed amount in today’s purchasing power, divide by that factor. Both calculations depend on the constant inflation assumption entered; neither obtains a personal forecast simply because a country or currency has been selected elsewhere on the site.
Check a one-year example
Take 1,000 and assume 5% inflation over one year. Something costing 1,000 today would cost approximately 1,050 next year under that assumption. Receiving 1,000 next year instead represents 1,000/1.05, approximately 952.38 in today’s purchasing power. The reduction is about 47.62 rather than exactly 50 because the percentage change is being measured from a different base.
Distinguish assumptions from historical indexes
This tool applies a fixed rate; it does not automatically load a country’s historical CPI series. A historical purchasing-power comparison should use the appropriate price-index ratio for the location and dates. Personal spending can differ from the official basket, and individual product prices may move differently. The result also does not predict exchange rates, wage increases or the return on a particular investment.
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