Nominal & Real Returns • ISA / Pension / GIA

Investment Return Calculator

Model lump sum and regular investments with compound growth. See nominal and inflation-adjusted real returns for ISA, pension and general investment accounts.

UK equity index funds: 7–9% historical nominal avg
Bank of England target: 2%. UK long-run avg: 2.5–3%
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Real value (inflation-adj.)
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Investment Returns: Nominal vs Real

A nominal return is the raw cash growth of your investment. A real return adjusts for inflation — it tells you how much your actual purchasing power has grown. For retirement planning, real returns matter most, because your spending in 20 or 30 years depends on what money can buy, not just how many pounds you hold.

Historic UK investment returns

Tax wrappers — ISA vs Pension vs GIA

ISA: No tax on growth, dividends or withdrawals. Funded from after-tax income. £20,000 annual allowance. Access at any age. Best for medium-term goals and flexibility.

Pension: Contributions receive tax relief (20%/40%/45%). Employer contributions are funded by the employer, up to the scheme’s cap. Growth is tax-free inside the pension. Up to 25% can usually be taken as a tax-free lump sum, capped at £268,275; the rest is taxed as income. Not normally accessible before age 55. Suited to long-term retirement saving.

GIA (General Investment Account): No annual limit. Capital gains above £3,000 (2026/27) taxed at 18%/24% (basic/higher rate). Dividends above £500 taxed at 10.75%/35.75%. Least tax-efficient but most flexible.

The power of starting early

Investing £150/month from age 22 to 67 at 7% nominal gives approximately £540,000. Starting at 32 gives only £270,000 — half the outcome for 10 fewer years. Time in the market, not timing the market, is the most powerful factor for long-run wealth.

Worked Examples

David — Lump sum ISA, 20 years
Initial£10,000
Monthly contrib.£0
Return / Inflation8% / 2.5%
Final (nominal)£49,268
Real value£30,067
CAGR8.0%
Rachel — Regular saver, 25 years
Initial£5,000
Monthly contrib.£300
Return / Inflation6% / 2.5%
Total invested£95,000
Final (nominal)£230,223
Growth£135,223
Tom — Pension, 35 years
Monthly (effective)£150/mo
Return / Inflation7% / 2.5%
Total invested£63,000
Final (nominal)£270,158
Growth£207,158

Frequently Asked Questions

UK and global equity index funds have historically returned 7–10% nominal per year over long periods. After inflation (2–3%), real returns of 5–7% are a reasonable long-run planning assumption. A balanced portfolio (60/40 equities/bonds) might target 5–7% nominal. Past performance does not guarantee future results — avoid assuming recent high returns will continue indefinitely.
Nominal return is the raw cash growth — what your portfolio grows to in pounds. Real return adjusts for inflation and tells you how much purchasing power you have gained. With 8% nominal returns and 3% inflation, your real return is approximately 4.85% (1.08÷1.03−1). For retirement planning, real returns matter most since your future spending depends on what money buys, not just the nominal amount.
They do different jobs. A pension gives tax relief on contributions (20–45%) and may carry an employer contribution, but the money is not normally accessible before age 55 and is taxable on withdrawal beyond the tax-free lump sum. An ISA offers no relief on the way in but can be withdrawn at any age without tax. Which suits you depends on when you need the money, your marginal rate now and in retirement, and whether your employer offers matching.
CAGR (Compound Annual Growth Rate) is the smoothed annual rate that would take an investment from its starting value to its final value over a given period. For example, a £10,000 investment growing to £49,268 in 20 years has a CAGR of 8%. It allows fair comparison across investments with different durations and is more useful than simple percentage gain (which ignores time).
Equity markets are volatile — values can fall 20–50% in a downturn (as in 2000–2002, 2008–2009, 2020). The key risk-management strategies are: (1) invest for the long term (5+ years) so short-term falls can recover; (2) diversify across geographies and sectors (a global index fund does this automatically); (3) keep an emergency cash fund so you do not need to sell investments during a downturn. This calculator shows projections at a steady rate — real returns will fluctuate significantly year to year.

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Written and reviewed by the UKCalc Editorial Team. UKCalc’s calculators and analysis are built and maintained using verified statutory data and official sources. Published by Animateed Limited. About UKCalc · Editorial policy · Methodology

Last reviewed: 9 August 2026 · Rates: 2026/27 tax year unless stated otherwise.

Rates, assumptions and sources

Which figures here are official and which are your modelling choices. Checked on 2 September 2026.

Official figures this calculator applies

UKCalc assumptions — not official figures

Past performance does not indicate future results. This is not advice, and no return shown here is promised or forecast.