Understanding Inflation and What It Does to Your Money
Inflation never appears on a statement. Your balance does not go down because of it, which is exactly why it is easy to ignore — the damage shows up in what the balance buys.
For anything longer than a few years, it is the largest single factor in whether a plan works.
Key takeaways
- At 3% inflation, prices double roughly every 24 years.
- Equities and real estate have historically outpaced inflation; cash and nominal bonds have not.
- A fixed-rate mortgage is itself an inflation hedge — you repay fixed debt with cheaper dollars.
- Any projection reporting a future balance without adjusting for inflation overstates it.
The arithmetic
At 3% annual inflation, prices double roughly every 24 years — a useful shortcut is the Rule of 72, dividing 72 by the inflation rate.
Someone retiring today spending $80,000 a year will need about $145,000 twenty years into retirement to maintain the same standard of living. A retirement plan built on today's expenses without that adjustment is not conservative; it is simply wrong.
What protects against it
Equities have historically been the most reliable long-run hedge, because companies raise prices along with everything else and earnings grow nominally. Real estate behaves similarly. A fixed-rate mortgage is itself a hedge — you repay a fixed nominal debt with progressively cheaper dollars, which is why inflation quietly benefits long-term borrowers.
Cash and nominal bonds are the most exposed. Treasury Inflation-Protected Securities adjust principal with the consumer price index, and Series I savings bonds pay a rate that resets with inflation, making both explicit hedges for money that must stay safe. Gold's record is far weaker than its reputation over horizons shorter than several decades.
Nominal versus real, in practice
Two approaches work for long-range planning. Project in nominal terms and deflate the final figure to today's dollars. Or use a real return assumption — roughly 4% instead of 7% — from the start, which produces a number already expressed in current purchasing power.
What does not work is projecting nominally and comparing the result against today's expenses. That is the single most common error in retirement planning, and it consistently produces plans that under-save.
Common questions
What inflation rate should I use for planning?
Three percent is the standard long-run US planning assumption and sits close to the historical average. If your spending skews toward healthcare or education, which have inflated faster, consider 3.5–4%.
Does a high-yield savings account beat inflation?
Barely, and rarely after tax. A 4.5% APY at a 24% marginal rate nets about 3.4%, roughly matching 3% inflation for a real return near zero. Savings accounts preserve money you need soon; they do not grow money you need later.
Who benefits from inflation?
Borrowers with fixed-rate debt, because they repay a fixed nominal amount with progressively cheaper dollars. Owners of real assets — property, equities, commodities — generally keep pace. Savers holding cash and lenders receiving fixed payments lose.