Inflation Forecast Calculator

Project future costs under multiple inflation scenarios — optimistic, baseline, and pessimistic

What is an inflation forecast calculator?

An inflation forecast calculator projects the future cost of goods, services, or expenses by applying compound inflation over a specified time period. Unlike a simple inflation calculator, it compares multiple scenarios simultaneously — letting you see best-case, expected, and worst-case outcomes side by side. This is essential for long-term planning where a single assumption can be misleadingly precise.

$
Scenario Mode
%

Custom (3%)

$134,391.64

+$34,391.64 (34.4%) over 10 years

Year-by-Year Comparison

Year3.0%
Year 1$103,000.00
Year 2$106,090.00
Year 3$109,272.70
Year 4$112,550.88
Year 5$115,927.41

How are inflation projections calculated?

Each scenario uses the compound inflation formula to project future costs. The calculator runs this formula independently for each rate, then compares the results to show how dramatically different assumptions affect your planning.

Compound Inflation Formula

Future Cost = Current Cost × (1 + inflation rate)ⁿ

Where inflation rate is the annual rate as a decimal (e.g., 0.03 for 3%) and n is the number of years.

Preset Scenario Rates

  • Optimistic (2.0%): Federal Reserve's stated long-run inflation target
  • Baseline (3.1%): BLS CPI-U historical average since 1913
  • Pessimistic (5.0%): Elevated scenario reflecting post-pandemic conditions

The scenario spread is the dollar difference between the highest and lowest projections. A large spread signals high planning uncertainty.

Why do inflation scenarios matter for financial planning?

Using a single inflation assumption for long-term planning creates a false sense of precision. The difference between 2% and 5% inflation on $100,000 over 20 years is more than $80,000. Scenario analysis reveals this uncertainty and helps you build plans that are robust across a range of outcomes.

How does category-specific inflation affect your costs?

The headline CPI averages all goods and services, but your actual costs depend on what you buy. Medical care has inflated at roughly 5.2% annually since 1960 — nearly double the headline rate. College tuition has averaged 4.8%. Meanwhile, electronics and apparel have actually deflated. If healthcare is your largest expense (as it is for many retirees), your personal inflation rate may be significantly higher than the national average.

What inflation rate should you use for retirement planning?

Financial planners typically recommend using 3–4% for general expenses and category-specific rates for known large costs like healthcare. The conservative approach: if your retirement plan works under 5% inflation, it will work under any realistic scenario. The Federal Reserve targets 2%, but achieving that target consistently has proven challenging — inflation has averaged 3.1% over the past century.

How does compounding amplify inflation over decades?

Inflation compounds like interest — each year's price increase applies to the already-inflated base. At 3% annually, prices double roughly every 24 years (the Rule of 72: 72 ÷ 3 = 24). At 5%, they double every 14.4 years. A 30-year-old planning for retirement at 65 faces 35 years of compounding — even at a modest 3%, prices will roughly triple during that period.

How does $100,000 grow under different scenarios?

Future cost of $100,000 at different inflation rates over various time periods
Time Period2% (Optimistic)3.1% (Baseline)5% (Pessimistic)Spread
5 years$110,408$116,478$127,628$17,220
10 years$121,899$135,670$162,889$40,990
20 years$148,595$184,062$265,330$116,735
30 years$181,136$249,469$432,194$251,058

Frequently Asked Questions

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