ISA calculators

Our free ISA calculators turn the rules into real numbers. See the interest a Cash ISA rate actually pays, what a Stocks and Shares ISA might return after fees, how much of your allowance the new £12,000 Cash ISA limit from April 2027 affects, whether an ISA beats an ordinary savings account after tax, and what the Lifetime ISA's 25% government bonus adds to your deposit.

A person pressing a button on a large glass calculator while another sits nearby holding coins

Cash ISA cap How much of your yearly Cash ISA saving the £12,000 limit from April 2027 affects, and what it would cost in tax outside an ISA.
Cash ISA interest What a rate is worth in pounds over any term, with a year-by-year balance chart.
ISA or savings account Whether a tax-free ISA rate actually beats a higher taxable rate, after tax.
Stocks and Shares ISA Growth after platform and fund fees, at three illustrative rates. Capital at risk.
Lifetime ISA Your 25% government bonus, your projected balance, and what an early withdrawal would cost.

Tax treatment depends on your circumstances and may change. This is not financial advice.