UK ISA Calculator
Project your tax-free ISA balance from yearly contributions within the annual allowance, and see how close you are to the limit.
Projected tax-free balance
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Total contributed —
Tax-free growth —
Allowance used this year —
Assumes the current £20,000 annual ISA allowance — verify the current-year limit at gov.uk.
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How it works
FV = balance × (1+r)ᵗ + yearly contribution × ((1+r)ᵗ−1)/r, all growth tax-freeFrequently Asked Questions
How much can I put in an ISA?
The annual ISA allowance covers all your ISAs combined (cash, stocks & shares, innovative finance, and Lifetime ISA) — commonly £20,000/year in recent years. Unused allowance doesn't carry over to the next tax year.
Why is a Stocks & Shares ISA better than a regular investment account for growth?
Every pound of growth, dividends and interest inside an ISA is entirely free of Income Tax and Capital Gains Tax, for life — no reporting, no tax return entries. Outside an ISA, gains above the CGT allowance are taxable.
What is a Lifetime ISA?
A LISA (for under-40s, up to £4,000/year of your allowance) adds a 25% government bonus toward a first home or retirement, but has withdrawal penalties for other uses — check the rules before choosing one.