Inflation Calculator

Applies one assumed constant annual inflation rate in two directions. It estimates the future amount needed to match an entered amount's purchasing power today, the cumulative price change, and the purchasing power today of that same nominal amount received in the future. It does not retrieve current or historical CPI data.

Enter a non-negative amount, a non-negative period in years and an annual inflation assumption above −100%. Fractional years are accepted. Use one currency consistently, choose a rate for the relevant country and period, and compare several scenarios when the future rate is uncertain.

For 1,000 over 10 years at a constant 3% annual rate, the price factor is 1.03^10 = 1.343916. A basket costing 1,000 today would therefore require about 1,343.92 in ten years, cumulative price growth is 34.39%, and a nominal 1,000 received in ten years would have purchasing power of about 744.09 today. Automated tests verify these figures.

Price factor = (1 + annual rate ÷ 100)^years. Future equivalent = amount × factor; cumulative price change = (factor − 1) × 100; present purchasing power = amount ÷ factor. Full-precision values are used internally and results display two decimals. Values that make the real-number result undefined or non-finite are rejected.

The forward result asks how many future currency units would buy what the entered amount buys today. The reverse result asks what today's purchasing power of the same future nominal amount would be. They use the same factor but answer opposite questions, so they should not be added or treated as two forecasts.

The entered rate is treated as one effective annual rate compounded for the exact year count. Actual inflation changes month to month and by category; a constant average does not reproduce the path of a real price index. A negative input models constant deflation, while −100% or lower is invalid because the price factor would become zero or leave this real-valued model.

Official consumer price indexes measure average price change for a weighted basket and specified population and geography. The U.S. Bureau of Labor Statistics notes that CPI only approximates cost of living and may not match an individual household's spending. Housing, food, healthcare, education and other personal weights can produce a different experience.

This currency-neutral scenario excludes exchange rates, taxes, wages, investment returns, substitutions, quality changes and category-specific prices. The CPI interpretation, nominal-to-real use and purchasing-power direction were checked against the U.S. Bureau of Labor Statistics CPI Handbook and purchasing-power factsheet; compounding against U.S. SEC Investor.gov education. Reviewed September 2026. It is not financial, investment, economic, tax or legal advice. Calculation runs locally and Quiklio does not upload the values.