Inflation Calculator

About Inflation Calculator

How Is Inflation Calculated?

The compound inflation formula adjusts money for price changes over multiple years:

Future value of prices: Future Price = Current Price x (1 + r)^n

Past-to-present adjustment: Today's Value = Past Amount x (1 + r)^n

Present purchasing power in the future: Future Buying Power = Current Amount / (1 + r)^n

Where r is the annual inflation rate and n is the number of years.

Worked example (past to present): What is $50,000 from 2000 worth in 2025 at 2.8% average inflation?

• $50,000 x (1.028)^25 = $50,000 x 1.999 = $99,950
• An income of $50,000 in 2000 needed to be roughly $100,000 by 2025 to buy the same goods
• Cumulative inflation over 25 years: 99.9%

Worked example (present to future): What will $100,000 buy in 20 years at 3% inflation?

• $100,000 / (1.03)^20 = $100,000 / 1.806 = $55,368
• Your $100,000 will only buy $55,368 worth of today's goods
• Purchasing power loss: 44.6%

Historical Inflation Rates

Annual inflation varies year to year but tends to average 2-3% in developed economies. Some context from recent decades:

Period	US Average (CPI)	UK Average (CPI)	Context
1960-1970	2.5%	3.6%	Post-war stability
1970-1980	7.4%	13.7%	Oil crises, wage-price spirals
1980-1990	4.7%	6.3%	Volcker rate hikes, gradual decline
1990-2000	2.8%	2.7%	Great moderation, low inflation
2000-2010	2.5%	2.1%	Tech bust, financial crisis, near-zero at end
2010-2020	1.7%	2.0%	Historically low, central bank targets
2020-2025	4.6%	5.1%	Pandemic stimulus, supply chain disruptions

For long-term planning (20+ years), using 2.5-3% for the US and UK is a reasonable assumption. The Federal Reserve and Bank of England both target 2% annual inflation.

How Inflation Erodes Purchasing Power

Even "low" inflation adds up over time. Here is how much $100,000 can buy in today's terms at different rates:

Years	At 2%	At 3%	At 4%	At 5%
5	$90,573	$86,261	$82,193	$78,353
10	$82,035	$74,409	$67,556	$61,391
15	$74,301	$64,186	$55,526	$48,102
20	$67,297	$55,368	$45,639	$37,689
25	$60,953	$47,761	$37,512	$29,530
30	$55,207	$41,199	$30,832	$23,138

At 3% inflation, money loses half its buying power in about 24 years. At 5%, it takes just 14 years. This is why cash savings that earn below the inflation rate are actually losing real value every year.

Why Inflation Matters for Retirement

Inflation is the silent risk in retirement planning. If you retire at 65 and live to 95, 30 years of inflation at 3% means prices will roughly double. A retirement income that feels comfortable at 65 buys only half as much by 85.

Example: You need $60,000/year in today's terms during retirement. If you retire in 20 years:

• At 3% inflation: you will need $60,000 x 1.806 = $108,367/year on day one of retirement
• At age 85 (35 years away): $60,000 x 2.814 = $168,842/year

This is why the retirement calculator includes an inflation adjustment. Always plan in "real" (inflation-adjusted) terms, not nominal.

Real Returns: Investment Growth Minus Inflation

The "real return" on an investment is the nominal return minus inflation. This is what actually grows your purchasing power:

Investment	Nominal Return	After 3% Inflation	Real Return
Savings account	4.5%	3.0%	1.5%
Government bonds	4.0%	3.0%	1.0%
Corporate bonds	5.5%	3.0%	2.5%
Global equities	8.0%	3.0%	5.0%
Cash under mattress	0%	3.0%	-3.0%

Cash in a savings account earning 4.5% while inflation runs at 3% gives you a real return of only 1.5%. Over 20 years, $100,000 grows to $143,000 in real purchasing power, not the $241,000 the nominal balance shows. Stocks have historically delivered 5-7% real returns, which is why they are the standard vehicle for long-term wealth building.

The Rule of 72 for Inflation

The Rule of 72 tells you roughly how many years it takes for prices to double: divide 72 by the annual inflation rate.

• At 2% inflation: prices double in ~36 years
• At 3%: ~24 years
• At 4%: ~18 years
• At 6%: ~12 years
• At 10%: ~7 years (roughly what countries like Turkey and Argentina have experienced recently)

Wage Growth vs Inflation

If wages grow faster than inflation, real incomes rise and living standards improve. If inflation outpaces wages, people get poorer in real terms even as their nominal pay increases. In the US, median real wages grew about 0.5-1% per year from 1990-2020 (wages grew at ~3%, inflation at ~2.5%). During 2021-2023, real wages fell for many workers as inflation spiked above 7% while wages lagged behind.

When negotiating a salary increase, anything below the inflation rate is effectively a pay cut in real terms. A 3% raise during 4% inflation means your purchasing power decreased by 1%.

To see how your savings can outpace inflation, the compound interest calculator lets you compare growth rates to inflation. For projecting investment growth in real terms, the investment return calculator shows the impact of inflation on long-term returns.

How the CPI Basket Works

The Consumer Price Index (CPI) measures inflation by tracking the price of a "basket" of goods and services that a typical household buys. The Bureau of Labor Statistics (BLS) in the US and the Office for National Statistics (ONS) in the UK each maintain their own basket.

The ONS basket contains around 730 items, reviewed every year to reflect changing habits. Recent additions include oat milk and electric vehicle charging. Items that fall out of fashion get removed (DVD recorders were dropped years ago). Each item carries a weight based on how much households spend on it. Housing has the largest weight (about 30% in the US CPI and roughly 26% in the UK CPIH), followed by transport, food, and recreation.

The BLS collects around 94,000 price quotes per month from about 23,000 retail establishments across 75 urban areas. The ONS collects roughly 180,000 prices each month from retailers across the UK. These prices are averaged together, weighted by spending patterns, and compared to the base period to produce the CPI number.

Core Inflation vs Headline Inflation

You will often see two inflation figures reported:

• Headline CPI: Includes everything in the basket, including food and energy prices. This is the number most people mean when they say "inflation."
• Core CPI: Strips out food and energy because those prices are highly volatile (oil prices can swing 30% in a few months). Core CPI gives a clearer picture of underlying inflation trends.

Central bankers focus heavily on core inflation when setting interest rates. During the 2022-2023 inflation spike, headline CPI in the US hit 9.1% (June 2022) while core peaked at 6.6% (September 2022). The gap between the two was mainly driven by energy prices. By early 2026, US headline CPI had settled to around 3.3% as of March 2026 and core to about 2.6%, according to BLS data.

In the UK, the ONS publishes CPI and CPIH (which includes owner-occupier housing costs). CPIH tends to run slightly lower than CPI because imputed rent is more stable than other components. As of early 2026, UK CPI was 3.0% and CPIH 3.2% as of February 2026.

Historical Hyperinflation Episodes

While developed economies typically see 2-5% inflation, some countries have experienced extreme hyperinflation where prices doubled in days or weeks:

Country	Period	Peak Monthly Rate	Price Doubling Time	What Happened
Hungary	1945-1946	4.19 x 10^16 %	15 hours	Post-WWII reconstruction, massive money printing
Zimbabwe	2007-2008	79.6 billion %	24.7 hours	Land reform collapsed agriculture, government printed money to cover deficits
Weimar Germany	1921-1923	29,500%	3.7 days	War reparations debt, political instability, money printing
Venezuela	2016-2021	~300% (sustained)	~25 days	Oil price collapse, economic mismanagement, sanctions
Yugoslavia	1992-1994	313 million %	1.4 days	War, loss of trade, monetary policy failure

Hungary's 1946 hyperinflation remains the worst ever recorded. At its peak, the government issued a 100 quintillion pengo banknote. Zimbabwe's 100 trillion dollar note from 2008 is now a popular novelty item. These episodes share common causes: governments printing money to pay debts combined with collapsing productive capacity.

Where Inflation Stands Right Now (Spring 2026)

As of March 2026, US headline CPI rose 3.3% over the previous 12 months, with energy prices a major driver (gasoline up 21.2% over the month). That is a notable jump from the 2.4% annual rate recorded in both January and February 2026, and above the Federal Reserve's 2% target. Core CPI (excluding food and energy) remained more contained at around 2.6% (BLS, April 2026).

In the UK, CPI held steady at 3.0% for both January and February 2026, according to the ONS. CPIH (which includes owner-occupier housing costs) was 3.2% over the same period. Food and non-alcoholic beverages prices rose 3.3% in the year to February 2026, down from 3.6% the month before. For context, the UK's 3.0% rate was higher than the EU average (2.1%), Germany (2.0%), and France (1.1%) in February 2026.

Both figures remain above the 2% target set by their respective central banks. The Bank of England base rate sits at 3.75%, while the Federal Reserve's federal funds rate reflects 175 basis points of cuts made during 2024-2025. If you are planning a major purchase or setting a savings target, using 3.0-3.5% as your inflation assumption for the next few years is more realistic than the long-run 2.5% average, at least until rates settle back toward target.

Inflation Protection: TIPS and Index-Linked Gilts

If inflation is your main concern, certain financial instruments are designed to protect against it:

• US Treasury Inflation-Protected Securities (TIPS): Issued by the US Treasury, TIPS adjust their principal value based on CPI changes. If inflation rises 3%, the principal increases by 3%, and interest is paid on the higher amount. You can buy TIPS directly at TreasuryDirect.gov or through ETFs like Vanguard's VTIP.
• UK Index-Linked Gilts: Issued by the UK Debt Management Office, these bonds adjust both their coupon payments and redemption value based on the Retail Prices Index (RPI). They are popular with pension funds that need to match inflation-linked liabilities.
• I Bonds (US): Sold by the US Treasury, I Bonds earn a composite rate made up of a fixed rate plus an inflation adjustment that changes every six months. The annual purchase limit is $10,000 per person electronically. During 2022, I Bonds briefly offered 9.62% annualized rates.

These instruments typically offer lower nominal returns than stocks, but they provide certainty that your money will at least keep pace with inflation. They are most useful for money you will need within 5-10 years, where stock market volatility could be a problem.

The Real vs Nominal Returns Formula

The quick approximation is: Real Return = Nominal Return - Inflation Rate. But the precise formula accounts for compounding:

Real Return = ((1 + Nominal Return) / (1 + Inflation Rate)) - 1

Example: Your portfolio returned 8% while inflation was 3%:

• Quick method: 8% - 3% = 5% real return
• Precise method: (1.08 / 1.03) - 1 = 4.85% real return

The difference is small at low rates but grows at higher values. At 15% nominal and 10% inflation, the quick method gives 5% real return, but the precise formula gives 4.55%. Always use the precise formula when inflation is above 5% or when compounding over many years. The future value calculator can help you project growth at any nominal or real rate.

To see how your savings can outpace inflation, the compound interest calculator lets you compare growth rates to inflation. For projecting investment growth in real terms, the investment return calculator shows the impact of inflation on long-term returns.

All calculations run locally in your browser. No data is sent anywhere.

Sources

• US Bureau of Labor Statistics - Consumer Price Index
• ONS - Consumer Price Inflation, UK: February 2026
• Federal Reserve - Monetary Policy and the FOMC
• Bank of England - Inflation and the 2% Target
• US Treasury - Treasury Inflation-Protected Securities (TIPS)
• UK Debt Management Office - Index-linked Gilts