Savings and ISA calculator
See how your savings grow with compound interest, in a cash ISA or a normal savings account.
Interest above your personal savings allowance (£1,000 basic rate, £500 higher rate, none at additional rate) is taxed. From April 2027 the cash ISA limit falls to £12,000 for under-65s. Assumes the rate stays the same.
ISA or savings account?
Interest in a cash ISA is always tax-free, and you can pay in up to £20,000 a year across all your ISAs. From 6 April 2027, under-65s can put at most £12,000 a year into cash ISAs.
Outside an ISA, the personal savings allowance lets basic-rate taxpayers earn £1,000 of interest a year tax-free and higher-rate taxpayers £500. Additional-rate taxpayers have no allowance.
Frequently asked questions
What is AER?
The annual equivalent rate shows what you would earn in a year with interest compounded, so you can compare accounts that pay monthly or yearly on the same basis.