Nominal vs. Real Returns: Why Inflation Changes What 'Growth' Means
Nominal return is the raw percentage growth in dollar terms, before accounting for inflation. Real return subtracts (approximately) the inflation rate from the nominal return, showing how much purchasing power actually grew — a 7% nominal return with 3% inflation represents roughly a 4% real return, the portion of growth that genuinely outpaced rising prices.
This distinction matters most for long-term goals, where the gap between nominal and real growth compounds into a meaningfully different picture of actual progress.
The basic adjustment
A simplified approximation: real return ≈ nominal return − inflation rate. A more precise calculation divides (1 + nominal return) by (1 + inflation rate) and subtracts 1, which matters more at higher rates but gives a very similar result to the simple subtraction at typical, moderate rates.
Why this matters for long-term planning
A retirement projection showing a large nominal future balance can be misleading if it doesn't account for inflation eroding that balance's real purchasing power over a multi-decade horizon — using a real (inflation-adjusted) return in a long-term projection gives a more honest picture of actual future purchasing power, rather than an inflated-looking nominal number.
When nominal figures are still the right ones to use
For short-term comparisons, or when comparing two investment options against each other over the same time period (where inflation affects both equally), nominal returns are perfectly fine to compare directly — the real-vs-nominal adjustment matters most when comparing across different time periods or translating a future dollar figure into today's terms.