Inflation Calculator: Future Cost & Purchasing Power

Two ways to look at inflation

Future cost asks how much money a purchase might require later. Purchasing power asks what an unchanged cash balance would be worth in today’s terms. Both results use your chosen annual inflation assumption.

Future cost = A × (1 + i)^y. Purchasing power in today’s money = A ÷ (1 + i)^y. A is the starting amount, i is annual inflation ÷ 100, and y is years.

Example: a 100 purchase

At a constant 3% annual inflation rate, a purchase costing 100 today would cost approximately 134.39 in ten years. Keeping 100 unchanged for that time would give approximately 74.41 of today’s purchasing power.

Is this a historical inflation calculator?

No. It does not load CPI series, predict national inflation, or compare specific calendar dates. Enter your own scenario. A negative rate models deflation, making future costs lower and unchanged cash worth more in today’s money.

Currency and rounding

Changing the currency changes labels only. It does not convert amounts using exchange rates. Annual projections use unrounded values, with results rounded for display.

About this calculator

Prepared by the UtilitiesWeb team at The Alpha 1 Company. Estimates are educational illustrations, not personalised financial advice, lending decisions, or guaranteed outcomes. Verify important decisions against provider documents and qualified advice where needed.

Methodology updated: 1 November 2026. Example rates and costs are assumptions, not live market quotes. Amounts are calculated at full precision and rounded for display.