A constant-rate scenario, not a forecast. Actual prices do not rise evenly.
Updates automatically as you type.
Calculated in your browser; your inputs are not sent to us. Privacy
Calculation details
Planning estimate only, not financial, tax, or legal advice. Verify assumptions and current rules before making decisions.
This tool runs in your browser. Your calculator inputs and results are never transmitted to us or to ad/affiliate partners. Ads and sponsored links may set third-party cookies to serve and measure them, but they never receive your calculation values. If you explicitly save a scenario, its permitted fields stay in local browser storage until you clear them. See our Privacy Policy.
Use this result
Share the current inputs or ask ChatGPT to explain the calculation in context.
More options
What does this calculator estimate?
Inflation calculator: see how rising prices shrink purchasing power and what goods will cost in the future at your chosen rate. Free, runs in your browser.
How this calculator works
Formula
Future cost = current amount × (1 + annual inflation rate)^years. Future purchasing power divides the current amount by the same cumulative factor.
Worked example
$1,000 with constant 3% annual inflation for 10 years corresponds to about $1,343.92 in future cost and about $744.09 of future purchasing power.
Assumptions to verify
- The entered inflation rate remains constant for the entire period.
- The model describes a general price-level scenario; individual goods can move differently.
- Taxes, investment returns, income growth, and currency changes are excluded.
Frequently asked questions
Is this an inflation forecast?
No. It is constant-rate scenario arithmetic using your assumption.
Why can my personal costs differ?
Households buy different baskets, and prices for individual goods do not move uniformly.
What does purchasing power mean here?
It is the amount of future goods the current sum could buy if the selected general price level compounded consistently.
Cite this tool
BoringToolsKit. “Inflation Impact Calculator.” boringtoolskit.com/inflation-impact-calculator/ (reviewed July 2026). Free to reference in articles, syllabi, and answer posts with a link.
Privacy: Inputs and results stay in this browser. Any future sponsored recommendation or advertisement will be clearly labeled and kept separate from the calculation.
A worked example: $1,000 at 3 percent for 10 years
Enter amount 1000, inflation rate 3, years 10. The growth factor is 1.03 raised to the 10th power, which is 1.343916. Future cost is 1000 x 1.343916 = $1,343.92. The nominal price increase is 1000 x (1.343916 - 1) = $343.92, so the same basket that costs $1,000 today would cost about $344 more a decade later at a constant 3 percent rate.
The buying-power side divides instead of multiplying. Future buying power of today's $1,000 is 1000 / 1.343916 = $744.09, and the buying-power loss is 1000 - 744.09 = $255.91. Notice the loss ($255.91) is smaller than the price increase ($343.92); they only coincide when the rate is near zero. That asymmetry is expected: losing a fraction of purchasing power is not the mirror image of gaining the same fraction on prices. Compare rates to see the compounding bite: at 2 percent over the same 10 years the factor is 1.218994, future cost $1,218.99; at 7 percent it is 1.967151, future cost $1,967.15, nearly double.
One shortcut worth checking against the calculator: the Rule of 72. Divide 72 by the annual rate to estimate the doubling time. At 6 percent, 72 / 6 = 12 years, and indeed 1.06^12 = 2.012196, so prices double in roughly 12 years. Use it as a mental estimate, then let the calculator produce the exact figure.
Boundary cases and where the model bends
At 0 percent inflation the factor is exactly 1 for every year count, so future cost equals the amount, buying power equals the amount, and both the increase and the loss are $0. At the negative boundary, a deflationary input like -2 percent with $1,000 over 10 years gives a factor of 0.98^10 = 0.817073: future cost drops to $817.07 and buying power rises to $1,223.89, so the calculator correctly shows deflation as a gain. Rates at or below -100 percent are rejected with an error because the factor would be zero or negative and division breaks. Amounts must be zero or positive; -5 is rejected, while 0 is accepted and returns $0 across every output. Years are capped at 100; anything above returns an error.
The model's main simplification is the constant rate. Real inflation varies year to year, so a single 3 percent assumption over 30 years can drift far from what actually happens; over long horizons, treat the output as a scenario, not a forecast. It also uses nominal USD with no tax treatment: gains in required cash do not trigger tax here, but real investments that keep pace with inflation usually do produce taxable nominal gains, which the calculator ignores. Finally, it prices one fixed basket of spending. Categories diverge sharply: over the last two decades medical care and college costs have grown faster than the headline CPI, while consumer electronics have fallen in price, so applying one rate to every expense overstates some costs and understates others. For retirement planning, run several rates side by side rather than trusting one.