# Buying Power Calculator

URL: https://speedycalculator.com/calculators/finance/buying-power/
Last updated: 2026-10-25

> The buying power calculator shows how the purchasing power of the dollar has changed between any two years since 1913 using the U.S. Consumer Price Index (CPI-U) – what an amount of money in one year is worth in another, and the cumulative and average yearly inflation.

## Inputs

- Amount
- In year
- Compared with year

## Results

- CPI in the first year
- CPI in the second year
- Equivalent buying power
- Value of $1 from the first year
- Cumulative inflation
- Average yearly inflation

## Formula

```
Equivalent amount = amount × CPI(target year) ÷ CPI(start year)
Buying power of $1 = CPI(start) ÷ CPI(target)
Average inflation = (CPI(target) ÷ CPI(start))^(1/years) − 1
```

## Explanation

A dollar in 1970 bought about as much as $8 does in 2025. CPI-U measures the average change in prices paid by urban consumers for a basket of goods and services; your personal inflation may differ. 2026 uses an estimate.

### How to use the Buying Power Calculator

- **Amount**
- **In year**
- **Compared with year**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter an amount, the year it is from and the year to compare with.

### Tips

- Use real (inflation-adjusted) figures to compare across years.
- Check whether data are seasonally adjusted.
- Use the same currency and base year throughout.
- Economic models simplify reality – treat results as illustrations, not forecasts.

### Common mistakes to avoid

- Mixing nominal and real values.
- Comparing percentage changes with percentage-point changes.
- Treating correlations as causes.

### Inputs explained

FieldWhat to enterAmountAmount in your currencyIn yearChoose one: 2026 (estimate), 2025, 2024, 2023 …Compared with yearChoose one: 2026 (estimate), 2025, 2024, 2023 …

### What each result means

- **CPI in the first year** = (([In year] - floor([In year]))×1000)
- **CPI in the second year** = (([Compared with year] - floor([Compared with year]))×1000)
- **Equivalent buying power** = [Amount]×[CPI in the second year]÷[CPI in the first year]
- **Value of $1 from the first year** = [CPI in the first year]÷[CPI in the second year]
- **Cumulative inflation** = ([CPI in the second year]÷[CPI in the first year] - 1)×100

### Example values

How the main result changes when **Amount** changes and everything else stays at the example values above:

AmountEquivalent buying power50123.1475184.72100246.29125307.86150369.43200492.58

## Worked example

Inputs — Amount: $100; In year: 1990; Compared with year: 2025.

Results — CPI in the first year = 130.7; CPI in the second year = 321.9; **Equivalent buying power = $246.29**; Value of $1 from the first year = $0.41; Cumulative inflation = 146.29 %; Average yearly inflation = 2.61 %.

## FAQ

**How much is $100 from 1990 worth today?**
About $246 in 2025 dollars, based on CPI-U.

**What is buying power?**
How much a given amount of money can buy.

**Which CPI is used?**
The CPI-U annual average published by the Bureau of Labor Statistics.

**What formula does the Buying Power Calculator use?**
Equivalent amount = amount × CPI(target year) ÷ CPI(start year).


## Sources

- [Federal Reserve Bank of Minneapolis – CPI 1913–](https://www.minneapolisfed.org/about-us/monetary-policy/inflation-calculator/consumer-price-index-1913-)
- [U.S. Bureau of Labor Statistics – Consumer Price Index](https://www.bls.gov/cpi/)