Real = Nominal × (Base index ÷ Period index); real rate ≈ nominal rate − inflation rate (exact: 1 + real = (1 + nominal) ÷ (1 + inflation))
What it is
A nominal amount is a figure exactly as quoted at the time — a wage, a bond's coupon, a country's output — counted in the dollars actually changing hands in that period. A real amount is the same figure restated to strip out the effect of changing prices, so it is expressed in the purchasing power of one chosen base period. Because prices drift over time, a nominal number can rise while the real number behind it falls. Note that "real" does not mean "more true" or "more accurate" — in economics it simply means "inflation-adjusted".
Why it matters
Almost every headline economic figure exists in both flavours, and mixing them up flips the conclusion. A savings balance paying a nominal rate below the inflation rate grows in dollars while losing purchasing power. Wages can climb in nominal terms and still buy less than before. Comparing two years of revenue, GDP or house prices without adjusting for inflation compares numbers taken with a ruler whose length changed in between. Knowing which version is being quoted tells a reader whether growth reflects more actual goods and services, or just higher price tags on the same ones.
How it's calculated
Real values come from nominal ones using a price index — usually the Consumer Price Index (CPI) for consumer amounts, or the GDP deflator (a broader index covering all national output). Each index has a base period set equal to 100, so every other period's level shows prices relative to that base. To restate a nominal amount in base-period dollars, divide it by the ratio of its own period's index to the base index. For rates, subtracting the inflation rate from the nominal rate is only a rough approximation; the exact Fisher relationship is (1 + real) = (1 + nominal) ÷ (1 + inflation). CPI is an index level — the inflation rate is its percentage change over a period.
Cross-border note. Inflation adjustment is country-specific: Canadian figures are adjusted using Statistics Canada's CPI, US figures using the U.S. Bureau of Labor Statistics CPI. The two agencies price different baskets and use different base periods, so a Canadian "real" number and a US one are not on the same measuring stick. Currency sits on top: a nominal Canadian-dollar return converted into US dollars is still a nominal figure.
FAQ
Does "real" mean the number is more accurate?
No. Real just means inflation-adjusted — restated in the purchasing power of a chosen base period. Both measures are legitimate; they answer different questions. Nominal counts the dollars that actually changed hands. Real counts what those dollars could buy compared with the base period. Neither is wrong, and neither replaces the other.
Can a real return be negative while the nominal return is positive?
Yes. If prices rise faster than the nominal rate, purchasing power falls even though the dollar balance grows. That is the whole point of the distinction — a nominal gain is not automatically a gain in what the money buys. The reverse can also happen: when prices fall (deflation), a real return can be larger than the nominal one.
Is CPI the same thing as inflation?
No. CPI is an index level — a number tracking the cost of a fixed basket of goods and services relative to a base period set at 100. The inflation rate is the percentage change in that index between two periods, usually year over year. So a rising index with a shrinking percentage change means prices are still going up, just more slowly — that is disinflation, not deflation.