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💰 UK Savings Calculator

See exactly how much your savings will grow over time with compound interest — works for ISAs, easy-access and fixed-rate accounts.

Calculate your savings growth
Final balance
Total deposited
Interest earned
Effective return
This calculator uses compound interest calculated monthly. For ISA accounts, interest is tax-free. For non-ISA accounts, you may be liable for tax on interest above your Personal Savings Allowance. Results are for guidance only.
Savings calculator — common questions
What is AER?

AER stands for Annual Equivalent Rate. It shows what the interest rate would be if it was paid and compounded once per year, making it easy to compare accounts. Always compare savings accounts using AER.

What is compound interest?

Compound interest means you earn interest on your interest. Over time this has a powerful effect — your money grows faster the longer you leave it. This calculator compounds monthly.

Should I use an ISA for my savings?

If you pay tax on savings interest, a Cash ISA lets you earn interest completely tax-free. The ISA allowance is £20,000 per tax year. For most people, a top easy-access ISA is a great place for savings.

What is the current best savings rate?

As of May 2026, the best easy-access savings accounts pay around 4.75% AER. Fixed-rate accounts and ISAs can pay slightly more. Check our Savings page for the latest rates.

How often is interest paid?

It varies by account. Some pay monthly, others annually. Monthly interest accounts allow you to compound your returns faster if you leave the interest in the account.

⚠️ This calculator is for guidance and illustrative purposes only. It does not constitute financial advice. Actual returns may vary depending on your account type, tax position, and whether rates change over time. Always check current rates directly with providers.