Budgeting & Income
Inflation Calculator
Inflation is a silent tax on cash. See both directions of its bite: what today's expenses will cost in the future at a given inflation rate, and what a dollar amount kept under the mattress will actually buy — a case for making long-term money outgrow the rate.
Formula shown below · Tested against worked examplesHow we verify
US CPI has averaged ~3% over the long run; the Fed targets 2%.
What today's amount will cost in 20 years: $18,061
What today's amount will cost in 20 years
$18,061
- What this cash will be worth in today's dollars
- $5,537
- Purchasing power lost
- 44.63%
Compare scenariosTry three values of one input
| Amount | |||
|---|---|---|---|
| What today's amount will cost in 20 years | $16,255 | $18,061+$1,806 | $19,867+$3,612 |
| What this cash will be worth in today's dollars | $4,983 | $5,537+$554 | $6,090+$1,107 |
Every other input stays at the value you set above — currently $10,000 for amount. Differences are measured against the first column.
Saved scenariosSave this calculation
Saved in this browser only — no account, and nothing is sent to us. Clearing your browser data deletes them.
How this calculator works
Future cost multiplies by (1 + rate)^years; purchasing power divides by the same factor. This is the constant-rate model — real CPI wobbles year to year, so treat results as a planning baseline (a historical-CPI mode using official BLS data is on our roadmap).
Formula
Future cost = Amount × (1 + i)ⁿ
Purchasing power = Amount ÷ (1 + i)ⁿ- Amount
- Today's figure
- i
- Annual inflation rate, as a decimal
- n
- Years
The two directions answer different questions: what something will cost later, and what a future sum is worth today. At 3%, $100,000 twenty-five years out buys about $47,761 of today's goods.
What this assumes
- A constant annual rate. Real inflation varies year to year and by category — housing, healthcare and education have run well above the headline.
- It applies the general rate to your figure; your personal inflation depends on what you actually buy.
- Historical purchasing power comparisons use published index values and reflect an average basket, not your basket.
What changes this number
- The rate assumed
- Small differences compound dramatically. At 3% prices double in 24 years; at 2% it takes 35.
- Time horizon
- The reason retirement planning must use real rather than nominal returns.
- Your spending mix
- Someone whose costs are dominated by rent or healthcare experiences more inflation than the index reports.
A worked example
Take the college in 15 years at 3% scenario. These figures are produced by the calculator above, not written alongside it, so they always match what the tool returns.
What you enter
- Amount
- $120,000
- Years
- 15 years
What it returns
- What today's amount will cost in 15 years
- $186,956
- What this cash will be worth in today's dollars
- $77,023
- Purchasing power lost
- 35.81%
Sources
This calculator uses no external data — the result follows entirely from the formula above and the values you enter, so there is nothing to cite beyond the arithmetic.
Calculator last reviewed August 9, 2026. How we verify
Try an example
Frequently asked questions
How does inflation work?
Prices rise a few percent a year on average, so each dollar buys slightly less. The effect compounds like interest in reverse: at 3%, prices double roughly every 24 years — meaning a fixed pile of cash loses half its real value over that span.
What inflation rate should I use for planning?
The Federal Reserve targets 2%; US CPI has averaged about 3% over the past century, with painful spikes (over 9% in mid-2022). Planning at 3% is the common default; stress-test important plans at 4%.
How do I protect savings from inflation?
Match the horizon to the tool: high-yield accounts and T-bills currently pay near or above inflation for short-term cash; for long horizons, assets with real growth — diversified stocks, TIPS (Treasury bonds indexed to CPI), I Bonds, real estate. The one guaranteed loser over decades is zero-yield cash.
Why do my retirement numbers need inflation adjustment?
Because a $1M nest egg 30 years from now buys what ~$412,000 buys today at 3% inflation. Either project in 'real' terms (subtract inflation from your return assumption) or inflate your spending target — mixing nominal returns with today's spending is planning's most common silent error.
Related calculators
Retirement Calculator
Project your retirement savings: what your balance could reach by retirement age and the monthly income it could sustainably provide.
Compound Interest Calculator
See how your savings grow with compound interest and monthly contributions — final balance, interest earned, and a year-by-year growth table.
Savings Calculator
Watch your savings account grow: enter your balance, monthly deposit, and APY to see the future value and every dollar of interest along the way.
Disclaimer: DayCents provides this calculator for educational purposes only. Results are estimates based on your inputs and the stated assumptions — they are not financial advice, a quote, or an offer of credit. Consult a qualified financial professional before making major money decisions.