Inflation: what higher prices do to purchasing power
Inflation is the silent tax that erodes the value of money: at 3% annual inflation, €10,000 loses about a quarter of its purchasing power in ten years. An inflation calculator compounds historical or projected rates over time to show what a sum of money will be worth in the future, or what amount you will need to buy the same goods and services later.
TL;DR
- Each year the price level multiplies by (1 + inflation rate)
- Compounded Cost Equation: Future Price = Current Amount × (1 + Rate / 100)^Years
- Example 1: $10,000 at 3% inflation over 10 years
How it works
Each year the price level multiplies by (1 + inflation rate). Over several years the effect compounds, so the future price of a good is the current price multiplied by the inflation factor raised to the number of years.
The math
Convert the annual inflation rate to a decimal, add 1 to form the yearly multiplier, raise it to the power of the number of years, and multiply by the current amount to get the future equivalent cost.
The exponent captures compounding: inflation in year two applies to the already-inflated year-one price, not to the original amount.
Examples
Example 1: $10,000 at 3% inflation over 10 years
- Current amount: $10,000
- Yearly multiplier: 1.03
- 10-year factor: 1.03^10 ≈ 1.3439
- Future equivalent: $10,000 × 1.3439 ≈ $13,439
Example 2: A €50 restaurant bill in 20 years at 2.5% inflation
- Current cost: €50
- Yearly multiplier: 1.025
- 20-year factor: 1.025^20 ≈ 1.6386
- Future equivalent: €50 × 1.6386 ≈ €81.93
When to use it
✦ Long-Term Financial Planning
Investors and retirees convert nominal savings goals into inflation-adjusted targets for realistic planning.
✦ Salary Negotiation
Workers measure whether a proposed raise beats inflation by comparing the real purchasing power increase.
⚠ Common Inflation Misconceptions
- Leaving Cash Idle: Money in non-yielding accounts loses real value every year; inflation makes idle cash a guaranteed loss of purchasing power.
- Confusing Nominal and Real: A 5% return with 3% inflation is only about 2% real growth, always compare in real terms.
- Using Single-Year Rates: Inflation varies yearly; long projections are sensitive to the average rate assumption.
FAQ (6)
What is purchasing power?
It is the physical quantity of goods and services that a unit of currency can buy at a given time.
How is inflation measured?
Governments track the change in consumer price indices (CPI), the average price of a basket of goods and services, over time.
If I type my salary or prices here, do you store them?
No — and that's deliberate. Everything runs locally in your browser, nothing leaves your device. We don't see your net salary, your margins, or the VAT numbers you test. For a finance tool that matters: you can run a quick check on a payslip or an invoice while on public Wi-Fi and close the tab knowing no trace is kept server-side.
Can I use it on the train without signal to check an invoice?
Yes. Load the page once, then it works offline. VAT, discount and mortgage math are all pure JavaScript — no API call. I often test it in airplane mode: open the mortgage page, type 250,000 at 4.5% for 25 years, you get the schedule instantly, even in a tunnel.
Can I file taxes with these results?
Use it as a fast sanity check, not as the final filing. Formulas are standard (e.g. Net = Gross / 1+VAT) and verified against official sources listed at the bottom, but rates and thresholds change — Italy's 22% vs Germany's 19%, or IRPEF brackets. For the actual declaration, double-check with your accountant or Agenzia delle Entrate / HMRC / IRS.
How do I send a calculation to my accountant?
Hit 'Share Link' under the results. It encodes the inputs in the URL — e.g. ?price=1200&vat=22 — so your accountant opens the exact same view, no screenshot needed. You can also copy the result with one tap and paste it into an email.
Sources & References
⚠ Financial Disclaimer
This tool provides estimates for informational purposes only and does not constitute financial, tax, or legal advice. Results may vary based on local regulations, rates, and individual circumstances. Always consult a qualified professional before making financial decisions.