Inflation Calculator

See what money was worth in the past or will be worth in the future. Enter an amount, an inflation rate and the years to get purchasing power.

All calculations happen locally in your browser. Nothing leaves your device.

Direction
$0.00
That amount will be worth $0.00 in today's money.

How Inflation Erodes Value

Every year of inflation shrinks what your money can buy, and because the effect compounds, the loss accelerates over time. A 3% annual rate sounds small, but after 100 years prices are roughly 19 times higher — meaning the same $100 buys about $5.20 worth of today's goods. Planning for this is why long-term savings are usually kept in interest-bearing or appreciating assets rather than cash under the mattress.

Compound formula
Future price level = amount × (1 + r)^n, where r is the annual inflation rate and n is the number of years. To go the other way, divide by (1 + r)^n — that's how this tool converts past amounts into today's money and vice versa.
Real interest rate
The real rate is the nominal rate minus inflation (roughly): if your savings earn 4% and inflation runs at 3%, your actual purchasing power grows by only about 1%. Negative real rates mean your balance is silently losing value even as the number goes up.
100 years at 3%
(1.03)^100 ≈ 19.2. So $100 today will need about $1,922 to buy the same basket of goods a century from now — and $100 from a century ago would have been worth only about $5.22 in today's money.

Frequently Asked Questions

What is inflation?

Inflation is the sustained rise in the overall price level of goods and services over time. When prices go up, each unit of currency buys less than before — that is, the purchasing power of money falls. It is measured as an annual percentage, most commonly with the consumer price index (CPI).

How is the inflation calculation done?

This tool uses compound growth: future value = amount × (1 + rate)^years and past value = amount ÷ (1 + rate)^years. Prices don't just add up year over year — each year's increase builds on the previous year's higher price level, which is what makes the exponential term appear.

What inflation rate should I use?

For long-term historical comparisons, the CPI for all urban consumers (CPI-U) is the standard. A common rule of thumb for the US is 3% per year as a medium-term average, though actual rates vary — they were below 2% in the 2010s, spiked to about 8–9% in 2022 and settled lower again after. Use the rate that matches the period you're comparing.

What is the difference between inflation and deflation?

Deflation is the opposite: a sustained fall in the general price level. With deflation, money buys more over time, so the same amount held back today is worth more later. Most modern economies target mild inflation (around 2%) because deflation tends to discourage spending and investment.

Is my data stored or sent anywhere?

No. The calculation is a simple exponentiation performed by JavaScript in your browser. Nothing is recorded, uploaded or shared, and clearing the inputs wipes everything.

Once the erosion is visible, plan around it: find your retirement number in the FIRE Calculator, try to outpace it with the Fixed Deposit Calculator, and hold the floor with the Emergency Fund Calculator.