How do I calculate what money was worth in the past?

To find the equivalent value of a past amount in today's money, use the formula: Equivalent today = Original amount × (1 + inflation rate)^years. For example, $100 twenty-five years ago at 2.5% average annual inflation is worth $100 × (1.025)^25 = $184.48 in today's dollars. Use the Purchasing Power tab of this calculator to compute this instantly.

How do I calculate the future cost of something?

Use the Future Value formula: FV = PV × (1 + inflation)^years. If a product costs $50,000 today and inflation averages 3% per year, in 10 years it will cost $50,000 × (1.03)^10 = $67,196. This is useful for projecting salary needs, retirement costs, or pricing long-term contracts.

What is a real (inflation-adjusted) return?

The real return strips out inflation from a nominal investment return. Use the Fisher Equation: Real return = (1 + nominal) / (1 + inflation) − 1. If your portfolio earns 9% nominally and inflation is 3%, the real return is (1.09 / 1.03) − 1 = 5.83%. A simpler approximation is 9% − 3% = 6%, but this slightly overestimates at higher rates.

What inflation rate should I use in the calculator?

This is a universal calculator — it does not apply country-specific CPI data. You can enter any rate you like. For historical analysis, look up the official CPI index for your country over the relevant period. Common long-run averages range from 2–3% for developed economies. For future projections, many financial planners use 2–3.5% as a conservative assumption.

Why does inflation matter for investments?

Inflation erodes the purchasing power of money over time. A 6% nominal return in a 3% inflation environment only delivers ~2.91% real growth in buying power. This is why investment returns are always more meaningful when expressed in real (inflation-adjusted) terms. Cash savings earning less than the inflation rate are losing real value even if the nominal balance grows.

Inflation Calculator

How much has money lost in value? What will things cost in the future? What is your real investment return after inflation? Three calculators in one.

Currency

All amounts displayed in selected currency

Original amount

Amount in the past (e.g. $100 twenty-five years ago)

Average annual inflation rate

Average inflation rate over the period (e.g. 2.5 for 2.5%)

Number of years

How many years ago (or how many years it covered)

Example: $100.00 25 years ago = $185.39 today at 2.5% avg inflation

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Estimates only. Uses a constant inflation rate — actual inflation varies each year. No country-specific CPI data.

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How to Use This Calculator

Tab "Purchasing Power"

Enter an original amount, the average annual inflation rate over the period, and the number of years. The result shows what that amount is equivalent to in today's money — and how much purchasing power has been lost. Use this to compare prices across decades or understand the real cost of holding cash.

Tab "Future Cost"

Enter today's current price of something (a salary, rent, a product, a service), an expected inflation rate, and how many years ahead you want to project. The result shows the future cost and the total increase. Use this to plan salary requirements, retirement income, or long-term budget projections.

Tab "Inflation-Adjusted Return"

Enter your nominal investment return (the stated or actual return before adjusting for inflation) and the annual inflation rate. The result shows your real return — the true growth in purchasing power. This uses the Fisher Equation, which is more accurate than simply subtracting the two percentages, especially at higher rates.

The Formulas

Purchasing power / Future value:
FV = PV × (1 + inflation)^years
where PV = present value, inflation = annual rate (decimal), years = number of years

Present value (what past money equals today):
PV = FV / (1 + inflation)^years

Purchasing power retained:
Retained = PV / FV = 1 / (1 + inflation)^years

Real return (Fisher Equation):
Real return = (1 + nominal) / (1 + inflation) − 1
where nominal = nominal investment return (decimal), inflation = inflation rate (decimal)

Simple approximation (less accurate at high rates):
Real return ≈ nominal − inflation

All calculations assume a constant inflation rate over the full period. Actual inflation varies each year. No country-specific CPI data is used — enter your own rate.

Worked Examples

Example 1 — Purchasing Power: $100 twenty-five years ago at 2.5% inflation

You want to understand what $100 in 2000 is worth in today's money, assuming an average 2.5% annual inflation rate.

Original amount (PV)$100.00

Inflation rate2.5% = 0.025

Years25

Equivalent today (FV)$184.48

Purchasing power lost$45.78 (of the $100)

Calculation: FV = 100 × (1.025)^25 = 100 × 1.8485 = $184.48. In other words, $100 today only buys what $54.22 bought in 2000 — nearly half the buying power has been eroded by inflation. Holding cash earns nothing in real terms.

Example 2 — Future Cost: $2,000/month rent today at 3.5% inflation for 10 years

A tenant paying $2,000/month in rent wants to know what equivalent rent might cost in 10 years if inflation averages 3.5%.

Current rent (PV)$2,000.00/month

Inflation rate3.5%

Years10

Future rent (FV)$2,813.86/month

Monthly increase+$813.86

Calculation: FV = 2000 × (1.035)^10 = 2000 × 1.4070 = $2,813.86. The monthly rent rises by $814 — that's an extra ~$9,766 per year. This also shows why salary growth must outpace inflation just to maintain the same standard of living.

Example 3 — Real Return: 9% nominal return, 3% inflation

An investor's portfolio returns 9% per year nominally. Inflation runs at 3%. What is the real (purchasing-power) return?

Nominal return9.00%

Inflation rate3.00%

Simple approximation6.00%

Real return (Fisher Eq.)5.83%

Calculation: Real = (1.09 / 1.03) − 1 = 1.0583 − 1 = 5.83%. The simple 9% − 3% = 6% approximation overstates by 0.17 percentage points. At low rates this difference is small, but at high-inflation environments (10%+), always use the Fisher Equation for accuracy.

Understanding Inflation: Key Concepts

Why Inflation Erodes Wealth

Inflation means the general price level rises over time. $1,000 in a jar for 20 years at 3% inflation buys only $544 worth of goods — the nominal balance is unchanged, but real purchasing power has been cut nearly in half. This is why money needs to be invested at a return that exceeds inflation just to maintain its value.

Nominal vs Real Returns

The nominal return is the stated return, before accounting for inflation (e.g. a savings account paying 4%). The real return is what you actually gain in purchasing power. If that 4% account exists in a 3% inflation environment, the real return is only about 0.97% — barely positive. When evaluating investments, always compare real returns, not nominal.

The Fisher Equation

Economist Irving Fisher formalised the relationship between nominal rates, real rates, and inflation: (1 + real) = (1 + nominal) / (1 + inflation). Rearranged: real = (1 + nominal) / (1 + inflation) − 1. The popular simplified version — real ≈ nominal − inflation — is a good approximation at low rates (below ~5%) but diverges meaningfully at higher rates. Use the exact formula for accuracy.

Compound Effect of Inflation

Like compound interest, inflation compounds. Even a modest 2% annual rate cuts purchasing power nearly in half over 35 years (0.98^35 = 0.499). At 4%, purchasing power halves in under 18 years. This is the core argument for investing — idle cash loses real value while invested assets can grow faster than inflation.

Using Your Own Rate

This calculator is intentionally universal — no country-specific CPI data is embedded. For historical analysis, research the official CPI for your country over the relevant period. For future projections, financial planners often use 2–3.5% for developed economies and 5–8% for emerging markets. Use conservative assumptions when planning retirement or long-term budgets.

Frequently Asked Questions

How do I find what $100 in 2000 is worth today?▼

Use the Purchasing Power tab. Enter $100 as the original amount, enter the average annual inflation rate for your country over that period (for example 2.5%), and enter 25 years. The calculator applies FV = 100 × (1.025)^25 = $184.48. This means you'd need $184.48 today to have the same purchasing power as $100 in 2000.

What inflation rate should I use for future projections?▼

This calculator lets you enter any rate. For long-run projections in developed economies, 2–3% is commonly used. Central banks in the US, EU, and UK target around 2%. For emerging markets, 5–8% or higher may be more realistic. For conservative retirement planning, many advisers use 3–4% to build in a margin of safety. Check your central bank's published inflation targets and historical averages for guidance.

What is the difference between nominal and real return?▼

The nominal return is what an investment reports — for example, 8% per year. The real return adjusts for inflation: if inflation is 3%, the real return is (1.08 / 1.03) − 1 = 4.85%. Real return tells you how much your purchasing power actually grew. A 5% return in a 6% inflation environment is a negative real return — you're losing buying power even while the number goes up.

How do I use this to plan a future salary?▼

Use the Future Cost tab. Enter your current salary as the current amount, enter an expected inflation rate (e.g. 3%), and set the number of years. The result is the salary you'd need in the future to maintain the same purchasing power. For example, a $50,000 salary today needs to become ~$67,196 in 10 years at 3% inflation just to keep pace — that's a required raise of $17,196 over the decade, or about 1.72% per year above actual pay.

Is this calculator accurate for all countries?▼

Yes — the mathematics is universal. The formula FV = PV × (1 + r)^t works in any currency and any country. What varies is the inflation rate you enter. For country-specific historical CPI data and local inflation calculators, use the "Calculate for your country" links below.

Why is my real return lower than I expected?▼

Inflation compounds just like returns do, which means the exact Fisher Equation calculation gives a slightly lower real return than the simple subtraction. For example, 8% nominal − 3% inflation looks like 5%, but the Fisher result is (1.08/1.03) − 1 = 4.85%. The difference grows at higher inflation rates. Also remember that returns may be taxable — taxes on the nominal return can further reduce your after-tax real return.

Can inflation be negative (deflation)?▼

Yes. Deflation means prices fall — the inflation rate is negative. In the calculator, enter a negative rate (e.g. −1 for −1%) to model deflation. In deflationary periods, the same amount of money buys more over time. However, deflation often accompanies economic downturns and can be harmful — it can reduce investment, increase the real burden of debt, and delay economic activity. Japan experienced prolonged deflation in the 1990s and 2000s.

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For country-specific inflation calculators that use official CPI historical data:

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