Inflation Calculator — Future Value of Money

How This Calculator Works

Inflation compounds the same way interest does — but in reverse. A 3% inflation rate means each year, the same nominal dollar buys 3% less.

Future Cost = Present Cost × (1 + i)^t

Real Value = Nominal Amount ÷ (1 + i)^t

Where i = annual inflation rate (decimal) and t = number of years. These two formulas handle the two directions:

Forward ("How much will $X be worth in t years?"):

• Future Cost = X × (1 + i)^t — what today's lifestyle will cost in t years
• Real Value = X ÷ (1 + i)^t — what $X saved today will buy in t years

Backward ("What is $X today worth t years ago?"):

• Equivalent Past Amount = X ÷ (1 + i)^t — what today's $X equals in past dollars
• Past Purchasing Power = X × (1 + i)^t — what today's $X would have bought back then

In the forward direction, a $50,000 lifestyle today at 3% inflation for 20 years: the same lifestyle will cost $50,000 × 1.03²⁰ = $90,305 in nominal dollars. Conversely, $50,000 saved today will have the purchasing power of $50,000 ÷ 1.03²⁰ = $27,684 in 20 years — a 45% erosion.

Purchasing power halves in ≈ 72 ÷ inflation rate (%) years

At 3% inflation, money loses half its value in 24 years (72 ÷ 3). At 5%, it halves in 14.4 years. At 8% (the 1970s peak), money halves in 9 years — a devastating erosion for savers. To compute real investment returns, use:

Real Return = (1 + nominal) ÷ (1 + inflation) − 1

A 10% nominal investment return at 3% inflation gives a real return of (1.10 ÷ 1.03) − 1 = 6.8%. Always plan in real terms — nominal numbers create false confidence. Common inflation benchmarks: U.S. long-run average about 3% (1913–2024); 1970s peak about 13.5% (1980); 2022 peak about 9.1% (post-pandemic); Japan 1990s–2010s near 0% (deflation); Venezuela 2020s hyperinflation over 1,000,000%. Use 3% for long-run U.S. planning; 2.5%–3.5% is the Federal Reserve's target range.

When to Use This Calculator

Use the inflation calculator when you want to:

• Plan retirement — how much will your savings buy in 20 or 30 years?
• Negotiate a salary — what raise do you need just to keep pace with inflation?
• Evaluate a long-term contract — is a fixed payment a good deal given future inflation?
• Compare investment returns — nominal vs real (inflation-adjusted) performance
• Teach children why "a dollar is not what it used to be"
• Adjust historical dollar figures to today's equivalent (or vice versa)
• Stress-test financial plans against high-inflation scenarios (5%, 8%, 10%)
• Compare salaries across decades — is a $50,000 salary in 2000 equivalent to $90,000 today?
• Adjust child support or alimony payments that are fixed in nominal dollars

Inflation expectations also drive investment allocation: when inflation runs hot, real assets (real estate, commodities, TIPS) and equities typically outperform cash and long-duration bonds. When inflation is low and stable, bonds and growth stocks tend to outperform. Always build inflation assumptions into your long-term financial plan — the difference between 2% and 4% inflation over 30 years is enormous.

Example Calculation

You have $100,000 in savings and want to know its purchasing power in 20 years, assuming 3% average inflation.

Forward direction:

• Future cost of today's $100,000 lifestyle: $100,000 × 1.03²⁰ = $180,611
• Real value of $100,000 saved today, in 20 years: $100,000 ÷ 1.03²⁰ = $55,368
• Inflation impact: $180,611 − $100,000 = $80,611 erosion per $100,000

So in 20 years, you would need about $180,611 to buy what $100,000 buys today — but if your $100,000 sits in cash earning nothing, it will only have $55,368 of real purchasing power. That is a $125,000 gap created entirely by inflation.

Backward direction: Someone says "my parents' house cost $40,000 in 1980." What is that in today's dollars (44 years, 3% inflation)?

• Equivalent today: $40,000 × 1.03⁴⁴ = $146,486

So $40,000 in 1980 is equivalent to about $146,000 today — meaning the house was actually quite expensive relative to typical 1980 incomes. (Actual U.S. inflation from 1980 to 2024 was higher, around 3.7%/year, giving an equivalent closer to $217,000.) For comparison at different inflation rates over 20 years: at 2% inflation, $100,000 grows to a $148,595 future cost and $67,297 real value; at 3%, $180,611 future cost and $55,368 real value; at 5%, $265,330 future cost and $37,689 real value; at 8%, $466,096 future cost and $21,452 real value. Small differences in inflation compound dramatically — which is why the Federal Reserve fights so hard to keep it near 2%.

The backward calculation is equally revealing for salary comparisons. If someone earned $30,000 in 1990, what is that worth in 2024 (34 years at 3% inflation)? $30,000 × 1.03³⁴ = $82,180 — meaning a $30,000 salary in 1990 had the purchasing power of about $82,000 today. This is why comparing nominal salaries across decades without inflation adjustment is misleading — always convert to real (constant-dollar) terms before drawing conclusions about whether someone was "better off" in a previous era.