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Inflation Calculator — What Will It Cost, What Is It Worth
Both directions of the same erosion: today's $10,000 at tomorrow's prices, and tomorrow's $10,000 in today's buying power.
A dollar keeps $0.55 of its buying power over 20 years at 3%.
How it works
Inflation is one process with two readings, and this page shows both at once. Reading forward: if prices rise a steady 3% a year, what does today's $10,000 of spending cost two decades from now? Reading backward: if someone promises you $10,000 twenty years out — an inheritance, a pension lump sum, a savings target you wrote down once and never revisited — what does that money actually buy in today's terms? It's the same exponent both times. You multiply going forward and divide coming back.
The defaults tell the story. At 3% a year, today's $10,000 of groceries, rent, and gas costs about $18,061 in 2046. Flip it around and a $10,000 check arriving in 2046 buys what $5,537 does now — each dollar quietly keeps only about $0.55 of its buying power. That's the red curve above: a single dollar's purchasing power, decaying year by year, no drama in any single year and a 45% haircut by the end. Nothing was lost or stolen; the number on the bill just stopped meaning what it used to.
This is why long-horizon money can't sit still, and why serious planning math works in real (inflation-adjusted) dollars instead of nominal ones. A retirement number that ignores inflation is a fiction with commas in it. ClariFi's planning and goal math thinks in today's dollars for exactly this reason — the answers come back in money you can feel, not money that will exist someday at a different size. To see the other side of the exponent — growth working for you instead of against you — the compound interest calculator is the mirror image of this page.
The formula
future = amount × (1 + rate)^years tomorrow's price of today's basket
worth = amount ÷ (1 + rate)^years today's buying power of a future amount
per-$ = 1 ÷ (1 + rate)^years what each dollar keeps
Example: $10,000 at 3% for 20 years
→ costs $18,061 · worth $5,537 · a dollar keeps $0.55
Honest assumptions
- One constant rate, compounded annually. Real inflation arrives unevenly — calm decades, sudden spikes — and the order matters to real households even when the average matches.
- The 3% default is a long-run US average shape, not a forecast. Actual CPI has run far above and far below it, sometimes within the same decade.
- Your personal inflation isn't the CPI. Rent, tuition, healthcare, and childcare each have their own curves, and your basket decides which ones you feel.
- This is a pure price-level conversion — no taxes, no investment returns, no wage growth modeled. It answers "what will it cost / what is it worth," nothing else.
- This page does arithmetic. It doesn't know the future — it's a starting point, not a plan, and not advice.
Questions people ask
What has US inflation averaged historically?
Over the past century, US consumer prices have risen roughly 3% a year on average — which is why it's this page's default. The average hides violent swings: double digits in the late 1970s, near-zero stretches in the 2010s, and a sharp spike in 2022. Use the slider to stress both ends rather than trusting any single number.
How fast do prices double?
The rule of 72 works for prices the same way it works for returns: divide 72 by the inflation rate to get the doubling time. At 3%, prices double roughly every 24 years; at 6%, every 12. It's an approximation, but it's accurate enough to make the point — at "normal" inflation, a working lifetime contains about two doublings.
Why does retirement math use real returns?
Because you'll spend at future prices, not today's. Quoting a portfolio's growth without subtracting inflation double-counts money that only exists to keep pace: 7% nominal growth during 3% inflation is about 4% of actual new buying power. Working in real returns keeps every projection in today's dollars, so "you'll have $1M" means what it sounds like it means.
Do wages keep up with inflation?
Over long stretches, wages in aggregate roughly track prices — but not smoothly, and not for everyone. Raises tend to lag spikes by a year or more, which is exactly when the squeeze hurts. If your pay hasn't moved lately, run it through the salary ↔ hourly converter and compare against what this page says the same paycheck now buys.
Related calculators
ClariFi makes tools, not advice. Nothing on this page is a recommendation to buy, sell, or sign anything.
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