Saving and cash · Calculator

How fast inflation
actually eats your savings.

Enter your savings, the inflation rate, and your APYAnnual Percentage Yield (APY)An annualized measure of deposit interest that includes the effect of compounding. It is not an inflation-adjusted or after-tax return.Full definition. See exactly how many years until you lose 10%, 20%, or 50% of your purchasing powerPurchasing powerWhat money can actually buy, not the number on the bill or in the account. Inflation shrinks it over time: by the BLS consumer price index, it takes more than $8 today to buy what $1 bought in 1971. Same dollar, much less buying ability.Full definition.

The question it answersHow many years until inflation erodes a set percentage of my cash savings?

Rules: United States. Data: defaults are dated snapshots; the assumptions give each date. Privacy: runs in your browser. What you enter stays on your device unless you copy a share link, which puts your inputs in the link.

PURCHASING POWER LOSS TIMELINE
SIDE BY SIDE
Account APY Real return Years to lose target

Moving savings from a big bank to an HYSA or money market fund is typically the single highest-ROI 15-minute decision in personal finance. See Where to Bank.

Projection, not a promise. The result follows the assumptions you enter. Real results will differ, sometimes by a lot.

What this tool assumes
  • Real return = (1 + APY) / (1 + inflation rate) - 1.
  • The inflation default is the latest CPIConsumer Price Index (CPI)The government's measure of how much a typical basket of consumer goods costs over time.Full definition year-over-year print (3.35% for the 12 months through August 2026, BLS CPIAUCSL via FRED), stamped at every build. This tool asks how fast inflation is eroding your savings right now, so the default tracks the current print rather than a long-run average. Edit it to test other rates.
  • Account presets are dated September 2026 rates: national average savings 0.37% as of September 21 (FDIC)[2], Amex HYSA 3.10% APY as of September 27[3], Fidelity SPAXX 3.46% 7-day yield as of September 24[4]. Actual rates vary.
  • Bitcoin return is a historical CAGRCompound Annual Growth Rate (CAGR)The steady yearly growth rate that would take an investment from its starting value to its ending value, with gains compounding. Example: $1,000 growing to $2,000 over 10 years is a CAGR of about 7.2%. It hides the ups and downs along the way, which matters for a volatile asset like Bitcoin. marker, not a prediction.

Not financial advice. Your numbers stay in your browser.

HOW THIS IS CALCULATED

This tool runs entirely in your browser: no data is sent to any server. The assumptions and default values behind the result are listed under “What this tool assumes” on this page. Verify the methodology or inspect the source code in your browser's dev tools.

Where to go from here

Read next

Cash Management

Money market funds, HYSAs, T-bills, CD ladders, I-bonds: each serves a different purpose.

Explore further
  • Cost of Living: 2026 vs 1971The price of a home, a car, a college degree, and a family in 1971 versus today.
  • Is Chasing Yield Worth It?A one-time bank or card bonus pays; hopping accounts for 0.2% and manufacturing spend is a low-wage hobby optimizing a 4% yield that still loses to inflation.
  • Real Inflation CalculatorConverts a budget from a past base year into today's dollars using official CPI and category-level breakdowns like housing, food, and healthcare.
  • Purchasing Power CalculatorShows what a dollar amount from one year is worth in another year's dollars using BLS CPI data back to 1913.

Sources

Bracketed numbers and verify badges in the text link to these sources. Figures, rates and rules change: check each source’s date before acting on it.

  1. U.S. Bureau of Labor Statistics, BLS CPI ↩
  2. Federal Deposit Insurance Corporation, fdic.gov/national-rates-and-rate-caps ↩
  3. High Yield Savings Account Online with no Fees | Amex US ↩
  4. Fidelity Investments, fidelity.com/go/manage-cash-rising-costs ↩

Calculators are educational estimates, not financial advice. Disclosures · How pages are reviewed