How is future purchasing power calculated?

Future value = Amount × (1 + rate/100)^years. For example, $1,000 at 3% inflation for 10 years becomes $1,000 × 1.03^10 ≈ $1,344 — meaning you would need $1,344 in the future to buy what $1,000 buys today.

How is past purchasing power calculated?

Past value = Amount ÷ (1 + rate/100)^years. This tells you what a historical dollar amount equates to in today's purchasing power, assuming a steady annual inflation rate.

What inflation rate should I use?

The US long-run average CPI inflation is roughly 3% per year. The 2010s averaged about 2%, while the early 2020s saw spikes above 8%. For conservative planning, 3–4% is a common assumption.

Does this use real CPI data?

No — this tool uses a fixed annual rate you provide, not live CPI data. For official historical CPI figures, use the US Bureau of Labor Statistics CPI calculator.

How do I reverse the inflation calculation?

Switch to "Past value" mode. Enter a historical amount, the assumed annual rate, and the number of years, and the tool divides by (1 + rate/100)^years to show what that money is worth in today's dollars.

Inflation Calculator

Name: Inflation Calculator
Availability: InStock
Author: Nham Vu

Enter an amount, an annual inflation rate, and a number of years to instantly see how purchasing power changes — forward or backward in time.

Inflation Inputs

Mode

Amount

Annual Inflation Rate

Number of Years

Currency Symbol

Fill in the inputs on the left and click Calculate

Equivalent in N years

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Starting Amount

—

Change

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Purchasing Power

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Year	Equivalent Value	Cumulative Change

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Summary

Enter an amount, an annual inflation rate, and a number of years to instantly see how purchasing power changes — forward or backward in time.

How it works

Choose "Future value" to project what today's money will buy in N years, or "Past value" to find what an old amount equals today.
Enter the starting amount in the Amount field.
Set the annual inflation rate (the historical US average is roughly 3%).
Enter the number of years.
Optionally choose a currency symbol for the display.
Click Calculate to see the result, purchasing-power change, and a year-by-year breakdown table.

Use cases

Estimate how much $50,000 in retirement savings will buy in 20 years at 3% inflation.
Understand what a 1990 salary of $40,000 is worth in today's dollars.
Plan a long-term budget by seeing how fixed costs erode under sustained inflation.
Compare the real cost of goods across different decades.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu