Inflation is the rate at which the general level of prices for goods and services rises, and subsequently, purchasing power falls. Central banks attempt to limit inflation, and avoid deflation, in order to keep the economy running smoothly.

What is purchasing power?

Purchasing power is the value of a currency expressed in terms of the amount of goods or services that one unit of money can buy. Inflation decreases the amount of goods or services you would be able to purchase with the same sum of money.

What is the difference between purchasing power decay and cost increase?

Purchasing power decay measures how a fixed sum of money (e.g., $1,000 cash in a safe) loses value over time. Cost increase measures how much a product or service that currently costs $1,000 will cost in the future due to inflation.

How is annual CPI inflation determined?

Inflation is typically measured by the Consumer Price Index (CPI), which tracks the average change over time in the prices paid by urban consumers for a market basket of consumer goods and services.

Inflation Calculator – Track Purchasing Power & Price Growth

The Devaluation of Fiat: How Inflation Functions

Inflation is a persistent macroeconomic force that expands the money supply relative to real economic output, resulting in general price increases. When prices double, the unit value of currency splits in half. A dollar does not change its printed numeral, but rather changes what that numeral can purchase in physical goods.

Inflation Equations

1. Future Cost of Goods

To find how much a product currently costing PV will cost in t years with an annual inflation rate of r:

FV_cost = PV × (1 + r)^t

2. Purchasing Power of Cash

To find the real purchasing value of a fixed currency reserve PV after t years:

FV_power = PV / (1 + r)^t

The absolute dollar loss is computed as: PV - FV_power.

Historical Consumer Price Index (CPI)

In practice, inflation rates fluctuation year-to-year. Economists compare purchasing power across eras by referencing CPI ratios:

Adjusted Value = Starting Amount × (Target CPI / Base CPI)

A constant 3% inflation rate represents a steady price expansion. Compounded over multiple decades, even single-digit annual inflation rates erode standard cash holdings by substantial margins.

Variable	Explanation
Future Cost	Price adjusted for inflation.
Present Cost	Base purchase price today.
i	Average annual inflation rate.
t	Time horizon in years.

Variable

Explanation

Future Cost

Price adjusted for inflation.

Present Cost

Base purchase price today.

Average annual inflation rate.

Time horizon in years.

Standard Parameter	10% Scale Factor	25% Scale Factor	50% Scale Factor
100	10	25	50
500	50	125	250
1,000	100	250	500
5,000	500	1,250	2,500
10,000	1,000	2,500	5,000

Standard Parameter

10% Scale Factor

25% Scale Factor

50% Scale Factor

100

500

125

250

1,000

100

250

500

5,000

500

1,250

2,500

10,000

1,000

2,500

5,000

Inflation Calculator.

Inputs

Inflation Summary

Purchasing Power Decay vs Product Cost Inflation

Annual Erosion Schedule

The Devaluation of Fiat: How Inflation Functions

Inflation Equations

1. Future Cost of Goods

2. Purchasing Power of Cash

Historical Consumer Price Index (CPI)

Formula & Calculation Theory

Variable Scale Reference Matrix

Real-World Case Studies & Scenarios

Beginner: Starter Inflation Scenario

Intermediate: Typical Family Inflation Scenario

Advanced: Pro Modeling Inflation Scenario

How the Calculation Works

Step-by-Step Worked Example

Practical Use Cases

Common Mistakes to Avoid

Interpreting Your Calculation Results

Authoritative Data References

Related Calculators

Educational Guides

Verified Trust Credentials

Frequently Asked Questions

How does the CalcyHQ Inflation Calculator work?

Is the Inflation Calculator free to use?

API Key Configuration