Inflation quietly erodes what money can buy, and this inflation predictor gives you five different ways to see exactly how much. Project a lump sum forward at any rate you choose, get a rate suggestion from historical CPI trends, see a Low/Expected/High range instead of a single guess, compare multiple rate scenarios side by side, or work backward from a future purchasing-power goal to find the nominal amount you’ll actually need.

How to use this inflation predictor

1. Select your Currency from the dropdown, or add a custom currency.
2. Choose a tab based on what you want to do: Predict Future Value, Auto-Suggested Rate, Range Forecast, Scenario Compare, or Goal Planner.
3. Predict Future Value: enter an Amount Today, Years From Now (or a Target Year), and your Assumed Annual Inflation Rate, then calculate.
4. Auto-Suggested Rate: enter your amount and years, choose a Trend Window (trailing 5 or 10 years), and the calculator suggests a starting rate from that currency’s historical CPI trend, which you can still edit.
5. Range Forecast: enter your amount, years, an Expected Annual Rate, and a Range Width (± percentage points) to see Low, Expected, and High outcomes side by side.
6. Scenario Compare: enter one amount and time horizon, then add up to 3 named rate scenarios to compare their outcomes directly.
7. Goal Planner: enter the Purchasing Power Needed in today’s money, your time horizon, and an assumed rate, and the calculator works backward to the nominal amount you’d need to plan for.
8. Review your results and export as PDF, Excel, or PNG depending on the tab.
9. Check View History to revisit past calculations across any tab.

What this inflation predictor does

Every mode in this calculator answers a version of the same underlying question, what does inflation do to money over time, but from a different angle depending on what you actually know or want to plan for. If you have a rate in mind, Predict Future Value handles it directly. If you’d rather start from something evidence-based, Auto-Suggested Rate gives you a historical CPI-trend starting point. If you don’t want to commit to one number at all, Range Forecast and Scenario Compare let you see a spread of outcomes instead of a single point estimate. And if you’re planning backward from a future need, Goal Planner flips the whole calculation around.

The core inflation formula

This compounds a constant assumed rate year over year, the same mathematical structure as compound interest, but applied to purchasing power loss rather than investment growth. The result tells you how many future dollars (or euros, rupees, or any supported currency) it would take to have the same buying power as your amount today, not what your money will literally be worth, since this formula measures the erosion of purchasing power, not a change in your account balance.

Predict Future Value: the direct approach

This is the calculator’s baseline mode: pick a rate, pick a time horizon, and see the equivalent value. The Target Year field auto-updates as you change Years From Now (and vice versa), so you can think in either “years from now” or a specific calendar year, whichever is more natural for your planning. The result includes “Purchasing Power Lost,” the percentage of your original buying power that the projected inflation would erode away over that period.

Auto-Suggested Rate: starting from historical data

Rather than guessing at an inflation rate from nothing, this mode suggests a starting figure based on your selected currency’s trailing historical CPI (Consumer Price Index) trend, over either a 5-year or 10-year window. This is explicitly a starting suggestion, not a guarantee, the calculator lets you override the suggested rate freely, since historical trends inform but don’t determine future inflation. The “Trend Source Rate” stat shows you exactly what historical figure the suggestion was built from, so you can judge for yourself whether recent history seems like a reasonable basis for your projection.

Range Forecast: acknowledging the uncertainty directly

No single inflation rate can be known in advance, which is exactly the idea behind this mode. Instead of one projected value, it returns three: Low, Expected, and High, built from your Expected Annual Rate plus and minus a Range Width you set in percentage points. This gives you a realistic band of outcomes rather than false precision from a single number, useful for stress-testing a financial plan against both a milder and a worse-than-expected inflation environment without running three separate calculations.

Scenario Compare: testing multiple assumptions side by side

This mode holds your amount and time horizon fixed while letting you name and compare up to 3 different rate scenarios directly, for example “Conservative,” “Historical Average,” and “High Inflation.” Because everything except the rate stays constant across scenarios, the comparison isolates exactly how much your assumed rate alone changes the outcome, which is often a more useful way to build intuition for how sensitive a long-term plan is to inflation assumptions than looking at any single projection in isolation.

Goal Planner: working backward from a target

This is the reverse of every other mode. Instead of starting with today’s amount and projecting forward, you specify the purchasing power you’ll need in the future, expressed in today’s money, and the calculator works out the larger nominal amount you’d actually need to plan for at that future date, given your assumed inflation rate.

This is the more directly useful framing for retirement or long-term savings planning, since “I want $50,000 of today’s purchasing power in 20 years” is usually the actual question, and this mode answers it directly rather than requiring you to work the standard formula backward yourself.

A note on accuracy

All figures produced by this calculator are theoretical projections based on a constant assumed rate, or a historical trend used only as a starting suggestion. Actual future inflation cannot be known in advance and may differ significantly from any rate used here, in either direction. This tool is not financial advice, and currency selection only changes the displayed symbol and formatting, it does not perform any live currency exchange-rate conversion.

Frequently asked questions