ISA Tax Savings Calculator
See exactly how much you could save in capital gains tax and dividend tax by investing inside a Stocks & Shares ISA compared to a General Investment Account. Visualise the power of your ISA tax shield over 5, 10, and 20 years.
Join millions of UK investors who use ISAs to grow their wealth tax-free
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Understanding the ISA Tax Shield
A Stocks & Shares ISA shelters your investments from both capital gains tax and dividend tax. This calculator models the cumulative benefit of tax-free compounding over time, showing you the true cost of investing outside an ISA.
Taxes Sheltered by an ISA
- Capital Gains Tax: 10% (basic) or 24% (higher/additional) on profits above £3,000 annual allowance
- Dividend Tax: 8.75% (basic), 33.75% (higher), or 39.35% (additional) above £500 annual allowance
- Income Tax: No tax on interest from bonds or cash within the ISA
- Withdrawal Tax: Withdrawals from an ISA are entirely tax-free at any time
Key ISA Rules (2025/26)
- Annual Allowance: £20,000 across all ISA types combined
- Tax Year: 6 April to 5 April — unused allowance cannot be carried forward
- Eligibility: UK residents aged 18+ (16+ for Cash ISA)
- FSCS Protection: Up to £85,000 per provider if the firm fails
Important Information
Capital at risk. The value of investments and the income from them can go down as well as up and you may get back less than you invest. Tax treatment depends on your individual circumstances and may be subject to change in future. This calculator provides estimates based on the assumptions entered and should not be considered personal financial advice. Past performance is not a guide to future returns.
Your Privacy Matters
This calculator runs entirely in your browser. No personal or financial information is collected, stored, or transmitted. Your data stays on your device.
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