ISA Calculator
Calculate your Stocks & Shares ISA or Cash ISA returns. See how your £20,000 annual allowance grows tax-free.
💰ISA Details
Annual ISA allowance: £20,000 (£1,667/month max)
Contributed
£245K
Tax-Free Growth
£373K
Contributions vs Growth
ISA Growth Over Time
Share Your ISA Projection
Encourage others to use their ISA allowance!
Tax-Free Returns
All gains, dividends, and interest inside an ISA are completely tax-free.
S&S vs Cash ISA
Compare Stocks & Shares ISA returns vs Cash ISA with different rates.
UK Specific
Uses the £20,000 annual ISA allowance for accurate UK projections.
How to Use
Choose ISA Type
Select Stocks & Shares ISA or Cash ISA.
Set Contribution
Enter monthly amount (max £1,667/month = £20K/year).
Set Return Rate
Typical: 6-10% for S&S ISA, 3-5% for Cash ISA.
View Growth
See tax-free ISA value and growth breakdown.
The Formula
FV = PV(1+r)^n + PMT × [((1+r)^n - 1) / r]Frequently Asked Questions
What is an ISA?
An ISA (Individual Savings Account) is a UK tax wrapper that allows you to save or invest up to £20,000 per year completely tax-free. No tax on interest, dividends, or capital gains.
What is the 2026 ISA allowance?
The annual ISA allowance is £20,000. You can split this across different ISA types (Cash, S&S, Innovative Finance, Lifetime) but the total cannot exceed £20K.
Cash ISA vs Stocks & Shares ISA?
Cash ISAs offer guaranteed but lower returns (3-5%). Stocks & Shares ISAs invest in the market for potentially higher returns (6-10%+) but with more risk. For long-term (5+ years), S&S ISAs typically perform better.
Can I withdraw from my ISA?
Yes, you can withdraw anytime. With a 'Flexible ISA,' you can replace withdrawn money in the same tax year without it counting towards your allowance.
Should I max out my ISA?
Yes! £20,000/year at 8% for 20 years = over £900,000 tax-free. The ISA is the single best tax shelter for UK investors.