Real Cumulative Inflation Calculator
Combine a starting price, monthly inflation, and time horizon to forecast nominal and real price changes after adjusting for income or productivity gains.
Illustrative finance tool; confirm critical projections with official economic data before making commitments.
Examples
- $850 starting price, 0.70% inflation for 18 months, 0.30% income growth ⇒ Nominal $963.72 | Real $913.13 | Real cumulative inflation 7.43%
- $1,250 starting price, 0.45% inflation for 12 months, no income adjustment ⇒ Nominal $1,319.20 | Real $1,319.20 | Real cumulative inflation 5.54%
FAQ
Should I use CPI or my own inflation estimate?
Use the inflation series that best matches what you buy—official CPI for broad baskets or a category-specific estimate for niche budgets.
How do I model an annual rate instead of monthly?
Convert the annual rate to a monthly rate by using (1 + annual rate)^(1/12) − 1, then enter the monthly percentage.
What does the real cumulative inflation value mean?
It shows how much purchasing power changes after accounting for income or productivity growth, so a lower number indicates less erosion.
Can this estimate salary adjustments?
Yes. Enter the current salary as the starting amount, inflation expectations, and the expected raise percentage in the optional growth field.
Additional Information
- Inflation compounding uses (1 + monthly rate)^months to capture cumulative price growth.
- Income or productivity growth deflates the nominal result to show real purchasing power change.
- Negative inflation (deflation) is supported by entering a negative monthly percentage.