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ISA Calculator
Calculate your ISA growth with tax-free returns on your UK savings and investments
CGT: 18% · Dividend tax: 10.75% (2026-27 rates)
Stocks & Shares ISA: UK equity average 6–8% long-term
Quick Tips
- 2025-26 & 2026-27 ISA allowance: £20,000/year — frozen until 2030/31
- Coming April 2027: Cash ISA limit for under-65s reduces to £12,000/year (overall £20,000 limit unchanged across all ISA types)
- All growth inside an ISA is completely tax-free — no CGT, dividend, or income tax
- Unused annual allowance is lost at 5 April — it does not roll over
- CGT on investments outside ISA (2025-26 & 2026-27): 18% basic / 24% higher rate. Annual exempt amount: £3,000
- Dividend tax 2026-27: 10.75% basic / 35.75% higher / 39.35% additional. First £500 tax-free (dividend allowance)
- Cash savings interest: taxed above Personal Savings Allowance (£1,000 basic / £500 higher rate) at your marginal income tax rate
- Since April 2024: you can open multiple ISAs of the same type in the same tax year