Savings Calculator
See how much your savings could grow with regular monthly contributions and compound interest over time.
% per year
years
Estimated final balance
£11,166
- Total paid in
- £10,000
- Interest earned
- £1,166
- Final balance
- £11,166
How do savings grow?
Savings grow in two ways: the money you add, and the interest you earn. With compound interest, you earn interest on your interest, so the balance grows faster the longer you leave it. This calculator applies interest monthly and adds your regular deposit each month.
The result splits your final balance into what you put in and what the interest added, so you can see the effect of saving regularly over several years.
Making the most of your savings
Even small monthly amounts add up. Saving regularly matters more than the exact interest rate over short periods, but over many years the rate makes a real difference thanks to compounding.
In the UK, an ISA lets you earn interest tax-free up to the annual allowance, which can improve your effective return compared with a standard savings account.
Worked example
Starting with £1,000 and adding £150 a month at 4% interest for 5 years gives a final balance of about £11,140. You would have paid in £10,000 and earned roughly £1,140 in interest.
Leaving it for 10 years instead grows the balance to around £23,300, with about £4,300 of that from interest.
Please note: Results are estimates and assume a fixed interest rate. They are not financial advice.
Frequently asked questions
Is interest really added monthly?
This calculator compounds monthly, which is common for savings accounts. Some accounts pay annually, which gives a slightly lower result over the same rate.
Does it account for tax?
No. It shows gross growth. Interest may be taxable above your Personal Savings Allowance unless it is held in an ISA.
What interest rate should I use?
Use the AER (annual equivalent rate) quoted by your account for the most accurate comparison.
Can I change the monthly amount later?
The calculator assumes a steady monthly deposit. To model changes, run it again with different figures for each stage.
Is this financial advice?
No. It is an illustration to help you plan and does not account for inflation, changing rates or your personal tax position.
Figures last reviewed on 13 August 2025.
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