Use our Inflation Calculator to see how the buying power of money changes over time. Convert a past amount into today’s value, deflate a future budget back to present-day dollars, or estimate projections using either Consumer Price Index (CPI) values or an assumed average inflation rate.
What the Inflation Calculator does
Prices don’t stand still. Over years and decades, inflation erodes purchasing power, while occasional deflation can increase it. The Inflation Calculator helps you translate an amount of money from one year into its equivalent in another year. Whether you are comparing historical wages, adjusting a long-term contract, or planning a future budget, this tool offers a quick, transparent way to normalize amounts across time.
Our calculator supports two popular approaches: applying an average annual inflation rate with compounding, or using CPI index values for the start and end periods. If you have reliable CPI data for your region, the CPI method is typically the most precise. If you only have a single inflation estimate for the horizon in question, the average-rate approach provides a reasonable projection.
How to use the tool
- Enter the original amount and choose your currency.
- Select the start year and the end year you want to convert to.
- Choose a calculation method:
- Average annual inflation rate: Provide an annual percentage (for example, 3%) and a compounding frequency (annual, quarterly, or monthly).
- CPI index values: Enter the CPI at the start year and the CPI at the end year. The calculator adjusts the amount by the ratio of these indices.
- Click Calculate to view the inflation-adjusted result, total price level change, and implied annualized rate.
Average-rate method explained
When you select the average-rate method, the Inflation Calculator compounds an annual rate over the number of years between your start and end dates. You can choose annual, quarterly, or monthly compounding to reflect how often prices effectively change. This is useful for forward-looking scenarios (for example, projecting five years into the future) or when you only have a single inflation estimate for your time span.
CPI index method explained
With CPI index values, the calculator applies a simple ratio: end CPI divided by start CPI. Multiplying your original amount by this ratio yields the equivalent value in the target year. This method is ideal for historical comparisons when official CPI series are available for your country or region. It avoids assumptions about compounding frequency and directly reflects observed price level changes.
Interpreting the results
The results include three key numbers: the inflation-adjusted amount in the target year, the total percentage change in prices over the period, and the implied annualized rate. The annualized rate helps you understand the average pace of inflation across the entire span, even when you used CPI ratios instead of a constant rate. If the end year precedes the start year, the tool returns a deflated figure, showing what the original amount would have been worth in earlier prices.
Practical use cases
- Historical comparisons: Compare the value of salaries, rents, or tuition between decades.
- Contract indexing: Adjust long-term agreements to maintain real purchasing power.
- Budget planning: Forecast future costs using a reasonable inflation assumption.
- Investment context: Translate nominal returns into real (inflation-adjusted) terms for clearer performance evaluation.
Accuracy tips
For the most accurate historical comparisons, use CPI indices that match your geography and the type of prices you care about (headline CPI vs. core CPI, national vs. regional). For projections, remember that inflation can vary, so consider testing multiple rate scenarios. Small differences in annual rates compound into large changes over long periods, so sensitivity analysis is valuable.
Limitations to keep in mind
No inflation calculator can capture every nuance of household spending or sector-specific price changes. The CPI is an average that may not reflect your personal basket of goods. Additionally, taxes, subsidies, and product quality improvements can affect perceived value beyond pure price level shifts. Treat results as estimates rather than exact conversions.
With these considerations, the Inflation Calculator offers a practical starting point for making money amounts comparable across time, informing smarter decisions in research, finance, and everyday life.