Inflation Calculator
Calculate the real purchasing power of money over time using a custom inflation rate — see what a past or future dollar amount is worth today.
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Enter your values and click Calculate
How It Works
Inflation adjustment uses compound growth: Future Value = Amount × (1 + Rate)^Years. To reverse it (find a past equivalent): Past Value = Amount ÷ (1 + Rate)^Years. The cumulative inflation percentage is (Future Value − Original) ÷ Original × 100. The "years until prices double" is derived from the Rule of 70: Years ≈ ln(2) ÷ ln(1 + Rate), which gives a precise answer (the Rule of 70 approximates this as 70 ÷ Rate%). All calculations assume a constant annual inflation rate throughout the period.
Examples
Savings Erosion
What $10,000 in savings will require in 10 years to maintain purchasing power.
Result: You'd need ~$13,439 in 10 years. You've lost $3,439 in real purchasing power. Prices double every ~23.4 years at 3%.
Salary Comparison
Finding the historical equivalent of a current salary to assess real wage growth.
Result: A $75,000 salary today equals ~$37,807 twenty years ago in real terms.
Retirement Planning
How much will $500,000 in savings be worth in real terms after 30 years of inflation?
Result: You'd need ~$1,213,631 in 30 years to match today's $500,000 purchasing power.
Frequently Asked Questions
What inflation rate should I use?
The US historical average is about 3% per year over the long run (1913–present). The Federal Reserve's target is 2%. Recent years (2021–2023) saw rates of 4–8%. For long-term retirement planning, 3% is a common conservative choice. For short-term projections, check the latest CPI data from the U.S. Bureau of Labor Statistics.
What is the difference between nominal and real value?
Nominal value is the face value in current dollars — the number printed on the price tag. Real value adjusts for inflation to reflect actual purchasing power. A salary that rose from $50,000 to $55,000 over 10 years with 3% annual inflation has a higher nominal value but lower real value, since $55,000 buys less than $50,000 did a decade ago.
How does the Rule of 70 work?
The Rule of 70 is a quick mental math shortcut: divide 70 by the annual inflation rate to estimate how many years it takes for prices to double. At 3% inflation, prices double in about 70 ÷ 3 ≈ 23 years. At 7% inflation, prices double in about 10 years. Our calculator uses the precise logarithmic formula rather than this approximation.
Does this calculator use real CPI data?
No — this calculator uses a fixed annual rate that you choose, not live CPI data. This makes it more flexible for scenarios (e.g. planning with a specific assumed rate) but less precise for calculating the exact historical change between two real years. For exact historical CPI comparisons, use the BLS CPI Inflation Calculator at bls.gov.