💰 ISA Calculator 2026/27

Tax-free savings growth using the £20,000 annual ISA allowance

£
Max £20,000 per tax year (2026/27)
%
yrs
£

ISA Growth Projection

ISA Value at End—
Total Contributed—
Tax-Free Interest Earned—
Growth Multiple—
💡 All returns within an ISA are completely free of income tax and capital gains tax — no matter how much you earn inside it.

ISA Allowance 2026/27

The annual ISA allowance is £20,000 per person for 2026/27. Any growth, interest, or dividends earned within an ISA are completely free from income tax and capital gains tax. The allowance cannot be carried forward — use it or lose it each tax year.

Types of ISA

  • Cash ISA — savings account with tax-free interest. FSCS protected up to £85,000.
  • Stocks & Shares ISA — invest in shares, funds, ETFs, bonds. Higher potential returns with higher risk.
  • Lifetime ISA (LISA) — for first home buyers or retirement. 25% government bonus on up to £4,000/yr. Must be aged 18–39 to open.
  • Innovative Finance ISA — peer-to-peer lending. Higher risk, not FSCS protected.

ISA vs Savings Account

With the personal savings allowance at £500 for higher-rate taxpayers and £1,000 for basic-rate taxpayers, an ISA becomes particularly valuable for anyone with significant savings or who expects to be a higher-rate taxpayer in future years. Long-term, the compounding benefit of tax-free growth is dramatic.

💡 Tip: You can split your £20,000 allowance across multiple ISA types in the same tax year, as long as you don't exceed the overall limit.