Future Value Needed
Purchasing Power Loss
Total Inflation Impact
Value of $1 Today in Future
Results assume a constant annual inflation rate. Actual inflation varies over time. This calculator is for guidance only.
Table of Contents
What your money will actually be worth
Inflation is the rate at which prices rise — and the rate at which your money loses purchasing power. This calculator shows how much you'd need in the future to match today's buying power, how a single dollar shrinks over time, and what that means for retirement and savings planning.
How inflation's impact is calculated
Inflation compounds the same way investment returns compound — just in the wrong direction for your wallet. The future cost of something that costs PV today, at inflation rate i over t years:
FV = PV × (1 + i)t
And the real value today of a future dollar (purchasing power of $1 in t years):
Real value = PV ÷ (1 + i)t
- FV — future value (amount needed later to match today's buying power)
- PV — present value (today's amount)
- i — annual inflation rate as a decimal (e.g. 0.03 for 3%)
- t — time in years
Worked example using the calculator's defaults ($10,000 today, 20 years, 3% inflation):
- PV = $10,000, i = 0.03, t = 20
- (1 + 0.03)20 = 1.8061
- FV = 10,000 × 1.8061 ≈ $18,061
- To match what $10,000 buys today, you'll need ~$18,061 in 20 years
- Equivalently, $10,000 stuffed in a 0%-interest envelope today will have the purchasing power of just $5,537 in 20 years (10,000 ÷ 1.8061)
This is why "saving" money in a low-yield checking account is actually a slow loss. To preserve real value, your money needs to grow at or above the inflation rate. To grow real wealth, your returns need to exceed inflation by a meaningful margin.
US inflation by decade (CPI data)
Historical inflation is highly variable, which is why "average inflation" can mislead planning:
| Decade | Average CPI inflation | Notes |
|---|---|---|
| 1960s | 2.5% | Stable, low; near Fed's modern target |
| 1970s | 7.1% | Oil shocks; peaked at 13.5% in 1980 |
| 1980s | 5.6% | Volcker shock broke inflation; gradual decline |
| 1990s | 3.0% | "Great Moderation" begins |
| 2000s | 2.6% | Low/stable except 2008 spike |
| 2010s | 1.8% | Persistently below Fed's 2% target |
| 2020–2023 | 5.0%+ average | Pandemic supply shocks; CPI peaked 9.1% June 2022 |
| 2024–2026 | 2.5–3.0% | Cooling toward Fed target |
What inflation does to a $100,000 savings balance
Holding $100,000 in cash with no interest earned, at different inflation rates:
| Time horizon | 2% inflation | 3% inflation | 5% inflation | 7% inflation |
|---|---|---|---|---|
| 5 years | $90,573 | $86,261 | $78,353 | $71,299 |
| 10 years | $82,035 | $74,409 | $61,391 | $50,835 |
| 20 years | $67,297 | $55,368 | $37,689 | $25,842 |
| 30 years | $55,207 | $41,199 | $23,138 | $13,137 |
At 3% inflation over 30 years, your $100,000 has the real purchasing power of about $41,000. At 5%, less than $24,000. This is why "play it safe by keeping cash" is anything but safe over long horizons.
Real vs nominal returns: the Fisher approximation
Investment returns reported in the news are almost always nominal (before inflation). Your actual gain in purchasing power is the real return:
real return ≈ nominal return − inflation rate
(For higher rates, use the exact Fisher equation: 1 + real = (1 + nominal) ÷ (1 + inflation).)
| Asset class | Long-term nominal return | Real return (after ~3% inflation) |
|---|---|---|
| US stocks (S&P 500, 1928–2024) | ~10.0% | ~6.8% |
| US bonds (10-yr Treasury) | ~5.0% | ~1.8% |
| US T-bills | ~3.4% | ~0.4% |
| Cash/savings (national average) | ~0.4% | −2.6% |
| High-yield savings (2025–2026) | ~4.5% | ~1.4% |
| Real estate (US, long-term) | ~8.0% | ~4.8% |
The big lesson: small differences in real return compound dramatically over decades. The 5-percentage-point gap between stocks (~6.8% real) and bonds (~1.8% real) means stocks roughly double real wealth every 11 years; bonds take ~39 years.
Investments that beat inflation
- I-bonds (TreasuryDirect). US savings bonds with a composite rate of a fixed yield + a CPI-tracking adjustment. Capped at $10,000/person/year. Cannot lose value. State-tax exempt. Best inflation-protected vehicle for most savers under the cap.
- TIPS (Treasury Inflation-Protected Securities). Marketable Treasury bonds where principal adjusts with CPI. No cap, but TIPS prices fluctuate with real rates — you can lose money if you sell before maturity in a rising-real-rate environment.
- Broad equity index funds. Best historical inflation hedge over 10+ year periods. Companies can raise prices in inflationary periods, so corporate earnings grow with inflation over the long run. Short-term volatility is high; long-term real returns are roughly 6–7%.
- Real estate (direct or REITs). Property values and rents tend to track inflation over long periods. REITs trade like stocks day-to-day but have inflation-protecting characteristics over multi-year horizons.
- Commodities. Can spike during inflation shocks (especially energy and food) but produce no yield and are highly volatile. Diversifying allocation, not a core holding.
Inflation and retirement planning
The most consequential inflation mistake in retirement planning is using nominal dollars to plan a 25–30 year retirement. If you retire at 65 with $1M and "live on $60,000/year," at 3% inflation that same lifestyle costs $109,000/year at age 90 — nearly double. A retirement plan that doesn't model this doubling effect is silently underfunded.
Two common approaches to handle this:
- Maintain growth exposure throughout retirement. A 60/40 stock/bond portfolio historically grows about 3–4% in real terms, so a 4% real withdrawal rate is roughly sustainable.
- Use inflation-protected income. Social Security has automatic COLAs based on CPI-W. Some pensions have inflation adjustments (most don't). TIPS, I-bonds, and inflation-adjusted SPIAs offer formal inflation protection but at the cost of lower starting income.
The widely-quoted "4% rule" already assumes inflation adjustments — you withdraw 4% of starting portfolio in year 1, then increase the dollar amount by inflation each year thereafter. It is NOT a 4% withdrawal each year of the current balance.
Limitations of this calculator
- Constant inflation assumption. Real inflation varies year to year. Use 2.5–3% for long-term US planning; consider scenarios at 4–5% for sensitivity testing.
- Headline CPI may not match your personal inflation. Healthcare, education, and housing have run well above CPI for decades. Younger renters in expensive cities often face 4–6% personal inflation when headline CPI shows 3%.
- Single currency. If you live in one country and earn/save in another, exchange rate movements can swamp inflation effects.
- Doesn't account for taxes. Inflation interacts with taxes in painful ways: nominal investment gains are taxed even when real gains are zero.
Sources & references
- US Bureau of Labor Statistics — Consumer Price Index — the official monthly CPI release, by category and region.
- Federal Reserve — Monetary Policy — FOMC statements, target inflation rate, and PCE inflation data.
- TreasuryDirect — I Bonds — official source for US inflation-linked savings bonds.
- TreasuryDirect — TIPS — Treasury Inflation-Protected Securities, the marketable inflation-linked Treasury bond.
- Bureau of Economic Analysis — PCE Price Index — the Fed's preferred inflation measure.
FAQs
Roughly 3.1% per year since the Federal Reserve was founded in 1913. But the average masks huge swings: 13.5% peak in 1980, near-zero in 2009–2015, then 9.1% in June 2022. The Fed's official target is 2% annually as measured by core PCE inflation. For long-range planning (retirement, college savings), most planners use a 2.5–3% assumption — high enough to be conservative, not so high that it overstates required savings.
Use the Rule of 72. Divide 72 by the inflation rate to get the doubling/halving time. At 2% inflation, prices double (purchasing power halves) in 36 years. At 3%, in 24 years. At 5%, in roughly 14 years. At 9% (US 2022 peak), in just 8 years. Over a 30-year retirement at 3% inflation, your fixed-dollar pension or annuity loses about 60% of its real purchasing power by the end — the same nominal income buys far less.
Both measure US inflation but with different baskets and formulas. CPI (Consumer Price Index, from BLS) tracks a fixed basket of urban consumer goods — it's the headline number most reported. PCE (Personal Consumption Expenditures, from BEA) is broader, captures shifts in spending behavior, and is the Fed's preferred measure for policy. PCE typically runs 0.2–0.4 percentage points below CPI. Social Security COLAs are CPI-W based; pension and annuity inflation adjustments vary.
Different roles. I-bonds (Series I Savings Bonds) earn a fixed rate plus an inflation adjustment tied to CPI-U — safe, simple, but capped at $10,000/person/year and have a 1-year holding minimum. TIPS (Treasury Inflation-Protected Securities) have no purchase cap and trade on the secondary market — better for large amounts or active portfolio management, but TIPS prices fluctuate with real interest rates so you can lose money if rates rise and you sell early. For most savers under $10K/year in inflation-protected exposure, I-bonds win on simplicity.
Headline CPI is an average; your actual cost-of-living increase depends on what YOU spend on. The biggest categories that diverge from CPI: housing (much higher in supply-constrained cities), healthcare (chronically above CPI, especially for older households), education (well above CPI for decades), groceries (highly variable). The BLS publishes inflation by category — if your spending is housing-heavy you might face 4–5% personal inflation in years when CPI shows 3%. Track your own grocery, rent, and insurance increases for a more accurate planning number.