Calculate how inflation erodes purchasing power and what your money is really worth after adjusting for rising prices. Live CPI data for 40+ currencies from the World Bank.
Calculator Parameters
$
$1K$100M
%
0.1%30%
%
0%30%
yr
1 yr50 yr
$
0100K/mo
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Future Value (Nominal)
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Real Value (Inflation-Adj.)
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Today's purchasing power
Total Interest Earned
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Inflation Erosion
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Purchasing power lost
Effective Real Rate
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Fisher equation
Total Invested
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Growth Over Time
Nominal
Real Value
Invested
Year-by-Year Breakdown
Year
Invested
Nominal Value
Interest Earned
Real Value
Real Gain
How the Inflation & Purchasing Power Calculator Works
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Compound Interest Formula
Uses A = P(1 + r/n)^(nt) where P is principal, r is annual rate, n is compounding frequency, and t is time. Monthly contributions are added using the future value of an annuity formula.
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Inflation Adjustment
Real value is calculated as Nominal ÷ (1 + inflation)^years. This converts your future balance back into today's purchasing power, showing what your money will actually be worth.
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Fisher Equation
The effective real rate uses the precise Fisher equation: (1 + nominal) ÷ (1 + inflation) − 1. This is more accurate than the simplified approximation of nominal minus inflation.
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Live Inflation Data
Click Live Rate to fetch the latest CPI inflation figure from the World Bank Open Data API (indicator FP.CPI.TOTL.ZG) — free, no API key required, updated annually.
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Rule of 72
A quick mental estimate: 72 ÷ interest rate = years to double. At 6%, money doubles roughly every 12 years. The calculator displays this live as you adjust the interest rate.
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40+ Currencies
Choose from over 40 global currencies organized by region. All values use Intl.NumberFormat for locale-accurate formatting — Indian Rupee grouping, Yen without decimals, and more.
How to Use This Calculator
The calculator answers one question: what will this money actually buy in the future? A balance can grow on paper while its purchasing power shrinks, and this tool shows both figures side by side.
Pick your currency. It is detected automatically from your location, but you can change it to any of 40+ currencies.
Enter a starting amount and, optionally, a monthly contribution.
Set the interest rate to what the money really earns, such as a savings account, a fixed deposit, or an expected long-run investment return. Use 0% for cash that earns nothing.
Set the inflation rate. Click Live Rate to load the latest World Bank CPI figure for your currency's country, or enter your own assumption.
Read the results.Nominal value is the figure on a future statement. Real value is what that figure buys at today's prices. The year-by-year table and chart show how the gap widens over time.
Typical ways people use it:
Checking a savings rate: if the effective real rate is negative, the account is losing purchasing power even though the balance rises.
Judging a pay rise: set the interest rate to 0% and the period to 1 year to see what last year's salary is worth now, then compare it with your new salary.
Planning for a future cost: see how much a fixed sum, such as an emergency fund or a down payment target, needs to grow just to stand still.
Understanding fixed incomes: model a pension or annuity that isn't inflation-linked to see how its buying power declines over 20–30 years.
Comparing countries: switch currencies to see how the same savings plan fares under different inflation environments.
The results are estimates based on constant rates. Real inflation and returns vary from year to year, so treat the output as an illustration, not a forecast or financial advice.
What Is Inflation?
Inflation is the rate at which the general price level of goods and services rises over time, reducing what each unit of currency can buy — a measure economists call purchasing power. When inflation is 5%, something costing $100 today will cost $105 next year.
Central banks such as the U.S. Federal Reserve and the Bank of England target annual inflation around 2% — low enough to encourage spending and investment, high enough to guard against deflation. Understanding inflation is fundamental for evaluating savings, wages, pensions, and any long-term financial plan.
Our country calculators pre-load local currency defaults, locale-accurate number formatting, and central-bank context. Select your country for a tailored experience with locally relevant historical data.
All live inflation rates are fetched from the World Bank Open Data API (indicator FP.CPI.TOTL.ZG — Consumer Price Index annual percentage change). This data is compiled from national statistical offices worldwide including the BLS (USA), ONS (UK), and MoSPI (India). Data may be 1–2 years delayed as statistical agencies compile annual figures.
The calculator uses the compound interest formula A = P(1 + r/n)nt and adjusts for inflation using the Fisher equation: real rate = (1 + nominal) ÷ (1 + inflation) − 1. Full details are available on our Methodology page and Data Sources documentation.
Last updated: 4 October 2026.
Frequently Asked Questions about Inflation
What is inflation and how is it measured?
Inflation is the rate at which the general price level of goods and services rises over time, reducing what each unit of currency can buy. It is most commonly measured using the Consumer Price Index (CPI), which tracks the cost of a representative "basket" of goods and services — food, housing, transport, healthcare, clothing — across time. When CPI rises 5% year-over-year, that figure is the inflation rate. Most central banks, including the U.S. Federal Reserve and the Bank of England, target 2% annual inflation as a healthy level.
How does inflation erode purchasing power?
Purchasing power is what a unit of currency can actually buy. When inflation runs at 5% per year, $100 today buys only $95.24 worth of goods next year. Over 20 years at 3% inflation, $10,000 in purchasing power requires $18,061 in nominal terms — meaning the price level nearly doubles. This calculator shows that erosion in real time, converting your nominal future value back to today's purchasing power using the formula: Real Value = Nominal ÷ (1 + inflation rate)years.
What is the Fisher equation and why does this calculator use it?
The Fisher equation calculates the true "real" interest rate: real rate = (1 + nominal rate) ÷ (1 + inflation rate) − 1. For example, a 7% nominal return during 3% inflation gives a real rate of (1.07 ÷ 1.03) − 1 ≈ 3.88%, not the 4% you would get by simple subtraction. The Fisher equation is more mathematically precise because it accounts for the compounding interaction between interest and inflation. This calculator always uses the full Fisher equation rather than the simplified approximation.
What is the Rule of 72 and how does it relate to inflation?
The Rule of 72 estimates how long until purchasing power is halved by inflation: divide 72 by the annual inflation rate. At 3% inflation, purchasing power halves in roughly 72 ÷ 3 = 24 years. At 6% inflation, it halves in just 12 years. For investments, the same rule applies in reverse: 72 ÷ interest rate = years to double your money. At 8%, money doubles in ~9 years. This calculator displays the Rule of 72 live as you adjust the interest rate input.
How does this calculator fetch live inflation rates?
Clicking the Live Rate button fetches the most recently published annual CPI inflation rate for the selected country from the World Bank Open Data API (indicator FP.CPI.TOTL.ZG). No API key is required. The data is sourced from national statistical offices — such as the Bureau of Labor Statistics for the US or the Office for National Statistics for the UK — and is typically 1–2 years delayed as statistical agencies compile annual figures.
What causes inflation to rise or fall?
Inflation has several root causes: demand-pull (too much money chasing too few goods, often during economic booms), cost-push (rising input costs such as oil prices or wages), monetary expansion (more currency in circulation reducing each unit's value), supply shocks (natural disasters or pandemics cutting the supply of goods), and imported inflation (a weaker currency making imports costlier). Central banks primarily combat inflation by raising interest rates, which slows borrowing and spending. Learn more in our What Is Inflation guide.
How does compounding frequency affect the calculation?
The calculator compounds the nominal (pre-inflation) growth at your chosen frequency — annual, semi-annual, quarterly, monthly, or daily — using A = P(1 + r/n)nt. More frequent compounding yields slightly more: at 7% over 20 years on $10,000, annual compounding gives $38,697, monthly gives $40,387 and daily gives $40,547 — a difference of roughly $1,850 between annual and daily. The real (inflation-adjusted) value is then derived separately using the Fisher equation, independent of compounding frequency.