Inflation Calculator – CPI & Purchasing Power Calculator

Calculate inflation, purchasing power, and real value of money. Use CPI data (1913-2025) or estimate future inflation with customizable rates.

Inflation Calculator

Calculate the equivalent value of the U.S. dollar in different years using three methods: Historical CPI data (1913-2025), forward flat rate inflation estimates, and backward flat rate purchasing power calculations.

💡 Tip: Choose your calculation method using the tabs below. All calculations are based on U.S. Consumer Price Index (CPI) data for urban consumers.

Inflation Calculator with U.S. CPI Data

Calculates the equivalent value of the U.S. dollar in any month from 1913 to 2025. Calculations are based on the average Consumer Price Index (CPI) data.

in
= ? in

Result

$137.04 in Sep. 2025 equals $100 of buying power in 2015 (Average).

The total inflation rate from 2015 (Average) to Sep. 2025 is 37.04%. The average inflation rate is 3.15% per year.

The CPI of 2015 (Average) is 237.017 and the CPI of Sep. 2025 is 324.8.

Purchasing Power Over Time

Forward Flat Rate Inflation Calculator

Calculates an inflation based on a certain average inflation rate after some years.

with inflation rate
%
after
years
= ?

Result

$100 now equals $134.39 after 10 years in purchasing power with an average inflation rate of 3%.

Backward Flat Rate Inflation Calculator

Calculates the equivalent purchasing power of an amount some years ago based on a certain average inflation rate.

with inflation rate
%
= ?
years
ago

Result

$100 now equals $74.41 of purchasing power 10 years ago with an average inflation rate of 3%.

Frequently Asked Questions

What is inflation?

Inflation is defined as a general increase in the prices of goods and services, and a fall in the purchasing power of money. Inflation can be artificial in that the authority (central bank, government, etc.) can control the supply of money in circulation.

The inflation rate itself is generally conveyed as a percentage increase in prices over 12 months. Most developed nations try to sustain an inflation rate of around 2-3% through fiscal and monetary policy.

What is the Consumer Price Index (CPI)?

The Consumer Price Index (CPI) is a measure of the average change over time in the prices paid by consumers for goods and services. The CPI is published monthly by the U.S. Bureau of Labor Statistics.

CPI Inflation Rate = (New CPI - Old CPI) / Old CPI × 100

This calculator uses CPI data to calculate the real purchasing power of money across different years.

How is inflation calculated?

Method 1: Using CPI

Inflation Rate = (CPI Year B - CPI Year A) / CPI Year A × 100

Method 2: Using Prices

Inflation Rate = (New Price - Old Price) / Old Price × 100

Method 3: Purchasing Power

New Value = Initial Value × (1 + Inflation Rate)^Years
What is purchasing power?

Purchasing power refers to the amount of goods and services that can be purchased with a unit of currency. As inflation increases, the purchasing power of money decreases because each unit of currency buys fewer goods and services.

Example: If inflation is 3% per year, money that buys $100 worth of goods today will only buy $97 worth next year (assuming no income increase).
What's the difference between inflation rate and CPI?

CPI (Consumer Price Index): A number measuring the average change in prices paid by consumers. It's an absolute value (e.g., 324.8).

Inflation Rate: The percentage change in CPI from one period to another. It shows how fast prices are rising (e.g., 3.15% per year).

Relationship: The inflation rate is calculated FROM the CPI. CPI is the data, inflation rate is what we derive from the data.
What causes inflation?

Common causes of inflation:

  • Demand-Pull Inflation: "Too much money chasing too few goods"
  • Cost-Push Inflation: Rising production costs (wages, materials)
  • Expansion of Money Supply: Central banks print more money
  • Supply Chain Disruptions: Limited goods availability increases prices
  • Import Costs: Currency depreciation makes imports more expensive
  • Expectations: If people expect inflation, they demand higher wages
Is inflation always bad?

Moderate inflation (2-3%) is actually beneficial:

  • Encourages spending and investment (not hoarding cash)
  • Reduces real debt burden
  • Allows real wages to fall without wage cuts
  • Provides room for monetary policy adjustments

High inflation (above 5%) is problematic:

  • Erodes savings value
  • Reduces purchasing power dramatically
  • Creates economic uncertainty
  • Hurts fixed-income earners
  • Can lead to hyperinflation if unchecked
How do I protect against inflation?

Strategies to protect your wealth from inflation:

  • Stocks: Historically outpace inflation long-term
  • Real Estate: Property values and rents typically rise with inflation
  • TIPS Bonds: Treasury Inflation-Protected Securities adjust with inflation
  • Commodities: Gold, oil, and other commodities rise with inflation
  • Diversification: Spread investments across asset classes
  • I-Bonds: U.S. savings bonds with inflation-adjusted rates
  • Wage Growth: Negotiate raises to keep pace with inflation
  • Debt: Borrow at fixed rates before inflation rises