Investment Return Calculator for United Kingdom – Cash ISA, FTSE, Gilts

Compare interest rates, tax benefits, and expected returns across UK options like Cash ISAs, FTSE 100 tracker funds, and government Gilts. Use our dynamic comparison tool below to run projections, adjust parameters, and compare net returns.

Compare Investment Returns Across Assets

Analyze Fixed Deposits, Stocks, and government bonds in real-time, adjusted for inflation and local taxes.

Target Country / Market
£100,000
5Years(60m)
Base Currency
Adjust for InflationShow real returns at UK inflation (2.80%)
Adjust for Taxes (Post-Tax)Deduct capital gains and slab taxes on returns
Top 3 Performing Assets
#1

Gold ETF (GBP)

medium·7.69%
£144,836Final Value
#2

Lifetime ISA (LISA)

medium·7.62%
£144,366Final Value
#3

SIPP (Pension Index Fund)

medium·7.50%
£143,563Final Value

Detailed Asset Comparison

Compare rates, calculate returns, and adjust interest rates in real-time.

Eligible
Ineligible
Gold ETF (GBP)HedgeMEDIUM RISK
Exchange-traded gold commodity fund backed by physical bullion, tracking GBP spot price.
Rate: 7.00–12.00% · Typical: 9.50%Compounding: annually · Rate Source: Source: LBMA Gold price historical long-term annualized CAGR.taxable:Subject to UK Capital Gains Tax upon disposal exceeding the annual CGT allowance.
Adjust Interest Rate
%
Expected Returns
£144,836Gain: +£44,836
Lifetime ISA (LISA)Tax FreeMEDIUM RISK
Tax-free savings account for first-time homebuyers or retirement, eligible for a 25% government bonus.
Rate: 7.00–11.50% · Typical: 9.00%Compounding: annually · Rate Source: Source: Balanced stock-bond index fund historical returns with government bonus applied.tax exempt (LISA Allowance) · Limit: £38/yr:All growth, dividends, and withdrawals are 100% tax-free if used for home purchase or after age 60.
Adjust Interest Rate
%
Expected Returns
£144,366Gain: +£44,366
SIPP (Pension Index Fund)RetirementMEDIUM RISK
Self-Invested Personal Pension offering tax relief on contributions, invested in long-term global equities.
Rate: 7.50–12.00% · Typical: 9.50%Compounding: annually · Rate Source: Source: Historical global equity index CAGR yields under UK pension wrappers.partially taxed · Limit: £570/yr:Tax relief at individual's marginal rate. Tax-free growth. 25% of maturity is tax-free; rest is taxed.
Adjust Interest Rate
%
Expected Returns
£143,563Gain: +£43,563
FTSE All-Share Index FundGrowthHIGH RISK
Broad market equity tracker capturing the performance of all eligible companies on the LSE.
Rate: 6.50–11.00% · Typical: 8.50%Compounding: annually · Rate Source: Source: FTSE All-Share Index historical dividend-reinvested returns.taxable:Dividends and capital gains are subject to UK tax unless held inside an ISA wrapper.
Adjust Interest Rate
%
Expected Returns
£140,124Gain: +£40,124
Stocks & Shares ISAPopularHIGH RISK
Equity investment savings wrapper that exempts all dividends and capital gains from UK tax.
Rate: 6.00–11.00% · Typical: 8.00%Compounding: annually · Rate Source: Source: FTSE 100 historical dividend reinvested long-term averages.tax exempt (ISA Allowance) · Limit: £190/yr:No Capital Gains Tax or Dividend Tax applies to investments held within the ISA wrapper.
Adjust Interest Rate
%
Expected Returns
£137,266Gain: +£37,266
UK Real Estate (REITs)YieldMEDIUM RISK
Listed UK Real Estate Investment Trusts offering commercial property exposure and yield.
Rate: 5.50–9.00% · Typical: 7.00%Compounding: quarterly · Rate Source: Source: London Stock Exchange (LSE) historical average UK REIT dividend yields.taxable:REIT dividends are taxed as property income. Exempt if held inside an ISA wrapper.
Adjust Interest Rate
%
Expected Returns
£133,892Gain: +£33,892
Corporate Bond FundYieldLOW RISK
Portfolio of sterling-denominated investment grade corporate bonds offering high yields.
Rate: 4.50–6.00% · Typical: 5.00%Compounding: semi-annually · Rate Source: Source: iShares Core £ Corp Bond UCITS ETF (SLXX) distribution yields, 2026.taxable:Subject to UK income tax on interest distributions exceeding the Personal Savings Allowance.
Adjust Interest Rate
%
Expected Returns
£129,074Gain: +£29,074
Fixed Rate Cash ISASafeLOW RISK
Savings account with a guaranteed interest rate for a fixed term, held inside the tax-free ISA wrapper.
Rate: 4.00–5.00% · Typical: 4.50%Compounding: annually · Rate Source: Source: Average UK commercial bank 1-5 year fixed cash ISA rates, 2026.tax exempt (ISA Allowance) · Limit: £190/yr:Interest earned remains 100% tax-exempt under ISA rules.
Adjust Interest Rate
%
Expected Returns
£126,417Gain: +£26,417
Cash ISATax FreeLOW RISK
Tax-exempt savings account providing fixed or variable interest returns for UK residents.
Rate: 3.50–5.20% · Typical: 4.30%Compounding: monthly · Rate Source: Source: Bank of England bank stats & NS&I Direct Saver interest rates, 2026.tax exempt (ISA Allowance) · Limit: £190/yr:Interest accrued inside the Cash ISA wrapper is 100% tax-free under UK rules.
Adjust Interest Rate
%
Expected Returns
£124,186Gain: +£24,186
Premium Bonds (NS&I)Tax FreeLOW RISK
Government-backed savings scheme where interest is distributed as monthly tax-free prizes.
Rate: 4.40–4.40% · Typical: 4.40%Compounding: annually · Rate Source: Source: National Savings and Investments (NS&I) Premium Bonds prize fund rate, 2026.tax exempt · Limit: £475/yr:All prizes won are completely tax-free and exempt from UK Income and Capital Gains tax.
Adjust Interest Rate
%
Expected Returns
£124,023Gain: +£24,023
UK Government GiltSovereignLOW RISK
Sterling denominated government bonds issued by the UK Debt Management Office (DMO).
Rate: 3.50–4.80% · Typical: 4.10%Compounding: semi-annually · Rate Source: Source: UK Debt Management Office (DMO) 10-year Gilt auction yields, 2026.partially taxed:Interest yields are subject to income tax; however, capital gains on Gilts are fully tax-exempt.
Adjust Interest Rate
%
Expected Returns
£120,001Gain: +£20,001

Opportunity Cost CalloutAlert

Choosing Cash ISA (4.30% Nominal Pre-Tax) over FTSE 100 index funds (7.50%) over 20 years costs you £188,832 in potential returns.

Portfolio Allocation

Risk-adjusted distribution for your £100k investment capital

Visual Split Bar
40%
35%
25%
Low Risk (Secure)
Medium Risk (Balanced)
High Risk (Growth)
Low Risk (Secure)40%
£40,000
Cash ISA8%
£8,000→ £9,915 (4.30%)
UK Government Gilt8%
£8,000→ £9,800 (4.10%)
Premium Bonds (NS&I)8%
£8,000→ £9,922 (4.40%)
Fixed Rate Cash ISA8%
£8,000→ £9,969 (4.50%)
Corporate Bond Fund8%
£8,000→ £10,241 (5.00%)
Medium Risk (Balanced)35%
£35,000
UK Real Estate (REITs)8.75%
£8,750→ £12,379 (7.00%)
Gold ETF (GBP)8.75%
£8,750→ £13,775 (9.50%)
Lifetime ISA (LISA)8.75%
£8,750→ £13,463 (9.00%)
SIPP (Pension Index Fund)8.75%
£8,750→ £13,775 (9.50%)
High Risk (Growth)25%
£25,000
Stocks & Shares ISA12.5%
£12,500→ £18,367 (8.00%)
FTSE All-Share Index Fund12.5%
£12,500→ £18,796 (8.50%)

Projected Portfolio Growth Timeline

Estimated compounding trajectory using historical typical returns.

Blended Return Rate:6.91%
5-Year Value
£140,401
Total Gain:+£139,451
10-Year Value
£198,978
Total Gain:+£198,028
20-Year Value
£410,328
Total Gain:+£409,378

Why this allocation?moderate strategy

Balanced Income & Market Growth: This allocation is designed to provide steady growth while managing volatility. By placing 40% in Low Risk assets to establish a stable income foundation, 35% in Medium Risk assets for balanced accumulation, and 25% in High Risk equity assets, your portfolio captures equity market upside while remaining insulated from sharp market downturns.

Frequently Asked Questions

How do I calculate investment returns?

Investment returns can be calculated using two main metrics: Absolute Return (for simple, short-term holding periods) and Compound Annual Growth Rate (CAGR) (for multi-year investments). You can calculate these by dividing the final value by the initial value, adjusting for time, or using our automated comparison tool.

What is CAGR and how is it used to compare investments?

CAGR (Compound Annual Growth Rate) represents the smooth annual rate at which an investment grows, assuming it compounded at a steady rate over a specific period. It is the gold standard for comparing investments of different tenures or asset classes, as it normalises returns on an annualised basis.

How do I compare returns from two different investments?

To compare two investments accurately, compare their CAGR (annualised returns), adjust for taxation (tax-free vs. capital gains vs. income tax slab), account for **risk** (volatility), and ensure you are comparing identical investment durations and cash flows.

What is the difference between absolute return and annualised return?

Absolute return is the total percentage gain or loss on an investment, regardless of the time it took (e.g., a 50% gain over 5 years). Annualised return (or CAGR) converts that total return into an equivalent yearly rate (e.g., a 50% absolute return over 5 years is roughly an 8.45% annualised return), allowing for fair comparisons.

How does compound interest affect investment returns?

Compound interest is the process where your investment earns interest on both the initial principal and the accumulated interest from previous periods. Over long horizons, compounding creates an exponential growth curve, which is why starting to invest early drastically increases your final maturity wealth.

What is the formula for calculating investment returns?

The formula for absolute return is: ((Final Value - Initial Value) / Initial Value) * 100. The formula for annualised return (CAGR) is: ((Final Value / Initial Value) ^ (1 / Years)) - 1. For regular contributions like a SIP, the Internal Rate of Return (IRR / XIRR) is used.

How do I compare ETF vs index fund returns?

ETFs and index funds track the same underlying index (like the S&P 500 or Nifty 50) and offer nearly identical returns. However, when comparing them, you must look at the tracking error (how closely they follow the index), expense ratio (annual management fees), and transaction costs (ETFs have brokerage commissions and bid-ask spreads, while index funds do not).

What is the average return on a savings account vs stocks?

Standard savings accounts offer low, safe yields of 1% to 3.5% (slightly higher for HYSAs), which rarely beat inflation. The stock market, represented by broad indexes like the S&P 500 or Nifty 50, has historically delivered long-term average returns of 8% to 12% per year (compounded), though it comes with short-term price volatility.

What investment has the highest return over 10 years?

Over a 10-year period, equity investments—specifically in high-growth sectors, technology indices (like Nasdaq-100), or diversified small/mid-cap equity mutual funds—have historically delivered the highest returns, often exceeding 12% to 18% CAGR, though they carry higher risk compared to fixed-income assets.

Which investment is safest with good returns?

Government-backed savings schemes (like PPF or Senior Citizens Savings Scheme (SCSS) in India, and Treasury Inflation-Protected Securities (TIPS) or CDs in the US) are the safest options that still offer reasonable, inflation-hedging returns. They carry virtually zero default risk because they are backed by the sovereign state.

What are the risks of comparing investments only by return rate?

Evaluating investments solely based on the return rate is dangerous. It ignores credit risk (probability of default), market risk (volatility), inflation risk (loss of purchasing power if return is low), liquidity risk (inability to withdraw funds when needed due to lock-ins), and tax erosion (which reduces net returns).