- Your AER (Annual Equivalent Rate) is converted into an equivalent monthly rate, so that compounding it monthly reproduces exactly the annual effective rate you enter. That rate is assumed to stay constant for the whole period modelled.
- This is a simplified monthly model. Real savings accounts may calculate or credit interest on a different schedule, including daily, so actual returns may differ slightly from this estimate.
- Monthly contributions are added at the end of each month.
- Results are shown before tax. UK savers may owe tax on interest above their Personal Savings Allowance — see our Savings Interest Tax Calculator to check.
- Results are illustrative estimates only, not a guarantee of any account’s actual return or financial advice.
Savings Calculator
See how your savings could grow with a starting deposit, regular monthly contributions and compound interest.
Year-by-Year Breakdown
Each row shows the contributions and interest added during that year, and your balance at the end of it.
Savings Goal Calculator
Work out the monthly contribution you’d need to reach a savings target by a chosen date.
Year-by-Year Breakdown
Each row shows the contributions and interest added during that year, and your balance at the end of it.
Savings Calculator UK
Our Savings Calculator has two tools in one. Use Savings Growth to see how a starting deposit and regular monthly contributions could grow with compound interest. Use Savings Goal to work backwards from a target amount and find out how much you’d need to save each month to reach it.
How to Use This Calculator
- Choose a tab: Savings Growth to project your balance forward, or Savings Goal to work out a required monthly contribution.
- Enter your starting deposit and, on the Growth tab, your planned monthly contribution.
- Enter your interest rate (AER) and the time period in years and months.
- On the Goal tab, enter your target amount instead of a monthly contribution — the calculator works out what you’d need to save each month.
- Click Calculate to see your projected balance, total contributions, total interest, and a year-by-year breakdown.
Important Assumptions
- Equivalent monthly rate derived from your AER. AER (Annual Equivalent Rate) already reflects a full year of compounding, so we convert it into an equivalent monthly rate — one that, compounded 12 times, reproduces exactly the AER you entered — rather than compounding the AER figure itself each month.
- Simplified monthly model. Real savings accounts may calculate or credit interest on a different schedule, including daily, so actual returns can differ slightly from this estimate.
- Constant rate. The rate you enter is treated as fixed for the whole period. Real savings rates, especially on variable and easy-access accounts, can change.
- Contribution timing. Monthly contributions are assumed to be added at the end of each month.
- Before tax. Figures are shown gross, before any tax on interest. UK savers have a Personal Savings Allowance, and interest above it may be taxable — see our Savings Interest Tax Calculator.
- Illustrative only. Results are an estimate for planning purposes, not a guarantee of any account’s actual return or a substitute for financial advice.
How Compound Interest Grows Your Savings
Compound interest means you earn interest not just on what you originally deposit, but on the interest you’ve already earned. The longer your money stays invested, and the more regularly you add to it, the more that compounding effect builds over time — which is why starting early can matter more than the size of any single deposit.
Savings Growth vs Savings Goal: Which Should You Use?
| You want to know… | Use this tab |
|---|---|
| “If I save £X a month, what will I end up with?” | Savings Growth |
| “How much do I need to save each month to hit £X by a certain date?” | Savings Goal |
Tips for Growing Your Savings
- Start with any amount. Even a small regular contribution benefits from compounding over time.
- Automate your saving. A standing order on payday can make regular contributions easier to keep up.
- Shop around for rate. Easy-access, notice, and fixed-term savings accounts can offer very different AERs — compare providers rather than sticking with your current account by default.
- Check your Personal Savings Allowance. Basic-rate taxpayers can usually earn up to £1,000 in savings interest tax-free, higher-rate taxpayers up to £500, and additional-rate taxpayers have no allowance — use our Savings Interest Tax Calculator to check your position.
- Consider an ISA if you’re likely to exceed your Personal Savings Allowance, since interest within an ISA is tax-free.
Frequently Asked Questions
How does compound interest work in this calculator?
AER (Annual Equivalent Rate) already reflects a full year of compounding, so this calculator converts your AER into an equivalent monthly rate — one that, compounded 12 times, reproduces exactly the AER you entered — and applies that monthly rate to your balance each month. This is a simplified monthly model; real savings accounts may calculate or credit interest on a different schedule, including daily, so actual returns can differ slightly from this estimate.
Does this calculator account for tax on my savings interest?
No, all figures are shown gross, before tax. Depending on your income and total savings interest, some or all of your interest may be covered by your Personal Savings Allowance, or may be taxable. Use our Savings Interest Tax Calculator to work out any tax due.
What does “Required Monthly Contribution” mean on the Savings Goal tab?
It’s the amount you’d need to save every month, in addition to your initial deposit, to reach your chosen goal by the end of the time period you entered, assuming your interest rate stays constant throughout. The figure shown is rounded up to the nearest penny, so following it should meet or slightly exceed your goal rather than leave you marginally short.
What happens if my initial deposit alone is enough to reach my goal?
If your initial deposit is projected to grow past your goal on its own, the calculator shows a required monthly contribution of £0 and explains that no further contributions are needed, based on the figures entered.
Are contributions assumed to be made at the start or end of the month?
This calculator assumes contributions are added at the end of each month. If your actual account credits interest or accepts contributions on a different schedule, your real results may differ slightly from the estimate shown.
Can I use this calculator for an ISA?
Yes, the growth mechanics are the same. The main difference is tax treatment: interest within an ISA is tax-free, so you don’t need to check it against your Personal Savings Allowance. For ISA-specific features like the Lifetime ISA government bonus, see our Lifetime ISA Calculator.
Does the interest rate stay the same for the whole period in this calculator?
Yes, the calculator assumes whatever rate you enter stays constant for the entire period modelled. In reality, many savings rates are variable and can change, especially on easy-access accounts, so treat longer-term projections as illustrative rather than guaranteed.
What’s the difference between this and the Compound Interest Calculator?
This calculator focuses specifically on straightforward savings planning, including working backwards from a target amount to find the monthly contribution needed on the Savings Goal tab. Our Compound Interest Calculator offers similar forward growth projections aimed at general investment, pension and ISA scenarios. Either can be used for basic savings growth; use whichever fits how you’re thinking about the numbers.
Does this calculator include inflation?
No, all figures are shown in today’s pounds without adjusting for inflation. The actual purchasing power of your future balance may be lower than the amount shown, depending on inflation over your savings period.
Why does the Year-by-Year Breakdown show a partial final year?
If your savings period isn’t an exact number of years, for example 10 years and 6 months, the final row covers only the remaining months rather than a full 12, and is labelled accordingly.