ISA Calculator
Calculate your tax-free savings with Cash or Stocks & Shares ISAs
Last updated: February 2026
ISA Type
Contributions
£
£
Annual: £2,400
Interest Rate
%
Typical: 3-5% (2025/26)
ISA Value After 10 Years
£38,075
100% tax-free
Tax-Free Growth
£9,075
You Contribute
£29,000
Growth
£9,075
Tax saved: £3,630
Total Return
31.3%
Within Allowance
Annual contributions: £7,400 of £20,000 (2025/26)
ISA Allowance 2025/26
£7,400 of £20,00037%
Remaining: £12,600
Tax Saved vs Taxable Account
Basic Rate (20%)
£1,815
Higher Rate (40%)
£3,630
Additional (45%)
£4,084
* Tax on interest if held outside ISA
Growth Over Time
Year 1
£7,680
Year 2
£10,483
Year 3
£13,414
Year 4
£16,481
Year 5
£19,688
Year 6
£23,043
Year 7
£26,551
Year 8
£30,221
Year 9
£34,060
Year 10
£38,075
Contributions
Growth
Understanding ISAs
💷 Cash ISA
- • Savings account with tax-free interest
- • Capital guaranteed (FSCS protected)
- • Fixed or variable rates available
- • Easy access or notice accounts
- • Best for: Short-term goals, emergency funds
📈 Stocks & Shares ISA
- • Invest in stocks, bonds, funds
- • Tax-free dividends & capital gains
- • Higher potential returns (and risks)
- • Not capital guaranteed
- • Best for: Long-term growth (5+ years)
🏠 Other ISA Types
Lifetime ISA (LISA): 25% government bonus for first home or retirement (age 18-39)
Innovative Finance ISA: Peer-to-peer lending with tax-free returns
ISA allowance: £20,000 for 2025/26 tax year (6 April - 5 April)