Inflation Calculator
Inflation Terms
Calculation Results
| Adjusted Amount | — |
|---|---|
| Years Applied | — |
| Inflation Rate Used | — |
How to Use This Inflation Calculator
Grandma's story about nickel candy sounds quaint until you run the numbers and realize your salary needs to double just to stand still. Inflation math is simple but easy to get backwards—I use Future Value when planning ahead and Past Value when comparing historical dollars to today.
- Choose a mode. Future Value for cost in Y years; Past Value for worth Y years ago.
- Enter amount today. The dollar figure in today's purchasing power.
- Enter annual inflation rate. Use CPI averages or a category-specific rate (e.g. 3% general, 5% tuition).
- Enter number of years—or a year range. Optional start and end years override the years field when both are filled.
- Press Calculate. Review adjusted amount, years applied, and inflation rate used.
Project college costs with the College Cost Calculator, or model retirement purchasing power with the Investment Calculator.
Inflation Formulas and Practical Applications
Inflation erodes purchasing power: the same basket of goods costs more in the future and required less money in the past. This calculator applies a constant annual rate—actual inflation varies year to year.
Future value
FV = PV × (1 + r)n
$10,000 today at 3% over 10 years needs about $13,439 to buy the same goods.
Past value
PV = FV ÷ (1 + r)n
$10,000 today was equivalent to about $7,441 ten years ago at 3% inflation.
Year range override
Entering start year 2015 and end year 2025 applies 10 years automatically—useful when you know calendar years but not the span off the top of your head.
Frequently Asked Questions
What is Future Value mode?
Future Value mode shows what today's dollar amount would need to be after n years of inflation to maintain the same purchasing power.
What is Past Value mode?
Past Value mode shows what today's amount was equivalent to n years ago at the entered inflation rate.
Can I use start and end years instead of a year count?
Yes. If both start year and end year are provided, the calculator uses their difference as the number of years applied.
Should I use CPI or a custom inflation rate?
This tool does not fetch live CPI data. Use a rate that matches your planning horizon—general CPI for broad estimates, or a higher rate for categories like tuition or housing.
What formula does this calculator use?
Future value equals present value times one plus rate raised to n years. Past value divides by the same factor.