Personal finance · 5 min read · 5 steps · Updated 18 October 2026

How to measure real returns on savings and investments

A 7% stock market return in a year with 4% inflation is really only a 3% real gain. Here is how to calculate the true, inflation-adjusted return on any asset — and why it matters for long-term financial decisions.

Investment returns quoted in financial media are almost always nominal — they do not account for the erosion of purchasing power caused by inflation. A savings account earning 4.5% in a year when inflation runs 3.0% has delivered a real return of approximately 1.5% — the amount by which your actual purchasing power increased. This guide explains how to apply this adjustment consistently across different asset types.

The data you need: the nominal return of your investment, and the CPI inflation rate over the same period. Both are freely available. Historical UK CPI is at ons.gov.uk; US CPI at bls.gov; international data at World Bank WDI.

The core formula: real return

The precise formula for real return is:

Real return = ((1 + nominal return) / (1 + inflation rate)) − 1

For small numbers, the approximation real return ≈ nominal return − inflation is accurate enough (within 0.1–0.2 percentage points). For large returns or high inflation environments, always use the exact formula.

Examples:
• Cash savings: 4.8% nominal, 3.0% inflation → (1.048/1.030) − 1 = 1.75% real
• UK equities (FTSE 100): 9.2% nominal, 3.0% inflation → (1.092/1.030) − 1 = 6.0% real
• US 10-year Treasury: 4.6% nominal, 3.2% inflation → (1.046/1.032) − 1 = 1.36% real

The real vs nominal distinction is fundamental: nominal returns tell you the number on your account statement; real returns tell you whether your purchasing power actually grew.

Applying it to cash and bonds

For cash savings accounts: use the annual interest rate as the nominal return and the CPI rate for the same year as the inflation rate. If you hold cash for multiple years, compound both — do not average.

For bonds: use the yield to maturity (YTM) or total return (coupon + price change) as the nominal return. Fixed-rate bonds do not adjust for inflation — their nominal return is fixed, so their real return varies with inflation. Inflation-linked bonds (UK index-linked gilts, US TIPS) adjust their principal for CPI, locking in a real yield — the real return is quoted directly when you buy them. The current real yields on TIPS are available at FRED (series DFII10 for 10-year TIPS).

Applying it to equities and property

For equities: take the total return (dividends + price appreciation), deflate by CPI. Over long periods (10–30 years), equities in the UK and US have delivered approximately 5–7% real returns — but with enormous year-to-year volatility. The Credit Suisse / UBS Global Investment Returns Yearbook is the authoritative source for long-run historical real equity returns across 35 countries, going back over 120 years.

For property: the return has two components — capital gain and rental income (or imputed rent if owner-occupied). Deflate the total by CPI. Also consider that property returns are sensitive to real interest rates — rising real rates reduce the discounted present value of future rents, pushing prices down even when nominal rents are rising. The ONS UK house price index provides nominal capital appreciation; add rental yield to get total return before inflation adjustment.

Long-run real returns: a useful benchmark table

Historical annual real returns for major asset classes (approximate, UK and US, 1900–2025, from Dimson, Marsh, Staunton research):

Equities (UK): ~5.4% per year real
Equities (US): ~6.5% per year real
Long-term bonds (UK): ~1.7% per year real
Long-term bonds (US): ~2.0% per year real
Cash / T-bills (UK): ~0.7% per year real
Cash / T-bills (US): ~0.4% per year real
Gold: ~1.0% per year real (highly volatile)

These figures show that cash has barely beaten inflation over the very long run. Bonds have delivered modest real returns. Equities have delivered the highest real returns but with the highest volatility — meaning there are extended periods (including the 1970s and 2022) when equities delivered sharply negative real returns. The implication for long-term financial planning: holding a large cash allocation for decades destroys purchasing power relative to inflation. Understanding this is the core reason financial advisers emphasise equities for long-horizon savings. Use our inflation explorer to see historical inflation in any country.

Use the TIPS breakeven as a market forecast

The TIPS breakeven inflation rate — the difference between nominal Treasury yields and TIPS real yields — is the financial market's implicit forecast of future CPI inflation. If the 10-year TIPS breakeven is 2.3%, the market expects average US CPI to run at 2.3% over the next 10 years. This is important for assessing real return expectations: if you hold a 10-year nominal Treasury at 4.6% and the breakeven is 2.3%, you are implicitly expecting a 2.3% real return — only if inflation actually comes in at 2.3%. If inflation surprises to the upside, your real return falls.

Current breakevens are available at FRED (T10YIE for 10-year breakeven). For the UK, the equivalent is derived from index-linked gilt yields versus conventional gilt yields — available from the Bank of England yield curves page. See also our guide on adjusting for inflation in personal finance for the practical spending side.

Sources & further reading

Terms in this guide

real vs nominal breakeven inflation rate real interest rate consumer price index cpi purchasing power

Frequently asked questions

What is a "real" return and why does it matter more than the nominal return?

A real return strips out the effect of inflation to show how much your actual purchasing power — your ability to buy goods and services — increased. Nominal returns are just the number your account statement shows. If inflation is 5% and your savings earned 4%, your account balance went up but your purchasing power went down: you can buy less than you could when you deposited the money. Over long periods, the difference compounds dramatically: £10,000 invested at 6% nominal for 30 years becomes £57,434. At 6% nominal with 3% inflation (3% real), the real value is only £24,272 in today's money. See the real vs nominal term for more detail.

Do equities protect against inflation?

In the long run, broadly yes — equities have delivered positive real returns over most 10-year periods in the UK and US. The mechanism: companies can raise prices as costs rise, protecting revenues and profits from inflation over time. However, in the short run, equities often fall when inflation rises sharply because: (1) central banks raise rates, increasing the discount rate for future cash flows; (2) consumer spending may weaken; (3) input cost pressures squeeze margins before pricing power catches up. The 2022 experience was a clear example — both equities and bonds delivered negative real returns simultaneously. Over a 10-year horizon, equities have been the best available inflation hedge — but not a perfect one in any individual year.

What is the breakeven inflation rate and how do I use it?

The breakeven inflation rate is the inflation rate at which an inflation-linked bond (TIPS or index-linked gilt) and a conventional bond of the same maturity produce the same total return. If the 10-year TIPS breakeven is 2.3%, then: if actual inflation over the next 10 years averages above 2.3%, TIPS outperform nominal Treasuries; if inflation averages below 2.3%, nominal Treasuries outperform. It is the market's consensus forecast of future inflation embedded in bond prices. Current US data: FRED T10YIE.