# Inflation Calculator

- **URL:** https://codeasystem.com/calculators/finance/inflation-calculator/
- **Category:** finance
- **Description:** Project what today’s prices will cost after years of inflation; and what tomorrow’s money will really buy.
- **Primary output:** What costs $1,000.00 today: $1,806.11 in 20 years

## Inputs
- Amount today (name: `amount`, type: number, prefix: $, example: 1000)
- Average inflation rate (name: `rate`, type: number, example: 3)
- Years ahead (name: `years`, type: number, example: 20)

## Outputs
- What costs $1,000.00 today: $1,806.11 in 20 years
- Future purchasing power of today’s money: $553.68
- Cumulative inflation: 80.61%

## Formula / methodology
```
Future cost = Amount × (1 + r)^t     Purchasing power = Amount / (1 + r)^t
```

At a constant inflation rate r, prices multiply by (1+r) every year. The same math in reverse tells you how much a fixed pile of money will actually buy after t years of rising prices.

## Assumptions & limitations
- One constant average rate; real-world inflation varies year to year.
- Long-run developed-market inflation has averaged roughly 2–3%; the US long-run average is near 3%.
- Not a historical CPI lookup; it projects forward from your chosen rate.

## Example
At 3% average inflation, a $1,000 expense today costs about $1,806 in 20 years; and $1,000 of cash kept idle buys only about $554 worth of goods.

Result for these inputs:

```
What costs $1,000.00 today: $1,806.11 in 20 years
```

## About this calculator
### Inflation is a quiet tax on idle cash

Money under the mattress loses purchasing power exponentially. This is the core argument for investing even conservative savings; returns must merely beat inflation for wealth to hold its real value.

### Choosing a rate

Central banks in developed economies typically target around 2%. Using 3% builds in a margin; using a recent spike overstates the long run. For salary negotiations, think in the same terms: a raise below inflation is a real pay cut.

## FAQs
### Can I look up historical CPI here?

No. Enter the average rate yourself; official CPI tables are published by national statistics agencies such as the U.S. Bureau of Labor Statistics.

### What rate should I use for planning?

2–3% suits long-term developed-market planning. For tuition or healthcare-specific costs, higher sector-specific rates are common.

### Why does purchasing power fall faster than prices rise?

They are mirror images: buying power divides by the same compounding factor that prices multiply by, so it decays slightly faster than a naive subtraction suggests.

## Related calculators
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- [Compound Interest Calculator](https://codeasystem.com/calculators/finance/compound-interest-calculator/)

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Last updated: 2026-08-23 · Version: 1.0.0 · [HTML version](https://codeasystem.com/calculators/finance/inflation-calculator/)