ISA Calculator UK: Estimate Growth, Returns & Tax Savings
Use this calculator to project the future value of a Stocks and Shares ISA, based on your starting balance, monthly investing, expected return and time horizon.
Based on UK ISA rules and the current £20,000 annual allowance.
Stocks and Shares ISA Calculator
This tool shows how your ISA could grow over time and estimates how much tax you may avoid by investing inside an ISA instead of a taxable account.
UK ISA allowance is currently £20,000 per year.
Projected ISA value at the end of your chosen timeframe.
How this ISA calculator works
This calculator uses monthly compounding to estimate long-term ISA growth. It also shows a simplified estimate of the tax you may avoid by holding investments inside an ISA wrapper.
It is designed for education and planning, not personal tax or investment advice.