Make your money work harder with a structured savings strategy.
It applies the annual interest rate you select as a monthly rate to your starting balance and assumes your regular contribution is added each month. The projection shows contributions and illustrative interest separately.
The calculator does not deduct tax, product charges or inflation and does not allow for changing contributions or interest rates. It is an illustration rather than a forecast or recommendation.
No. Savings and investment rates can change, and actual returns may be lower or higher. The result depends entirely on the figures and assumed rate entered.
Saving consistently is the foundation of every sound financial plan. Yet with hundreds of savings products available — ISAs, fixed-rate bonds, notice accounts, premium bonds — choosing the right one for your circumstances is rarely straightforward.
At Castle Stonebridge, we help you cut through the complexity. Whether you are building an emergency fund, saving for a specific goal, or looking to put excess cash to work in a tax-efficient wrapper, our independent advisers will design a savings strategy that is clear, purposeful, and reviewed regularly.
We understand what you're saving for, your timeline, how much day-to-day access you need, and your current savings position — including any ISAs, fixed-rate accounts, and other cash holdings.
We consider how your savings strategy would hold up against unexpected events — job loss, major unplanned expenditure, or a sustained period of low interest rates — ensuring the right balance of accessibility and growth.
We identify inefficiencies in your current savings — poor rates, unsuitable product types, or unused ISA allowances — and recommend a structured, tax-efficient approach matched to your goals and circumstances.
As independent advisers not tied to any single provider, we search the full market for the most competitive rates and appropriate tax wrappers — from Cash ISAs and Stocks & Shares ISAs to fixed-rate bonds and notice accounts.
We put your savings strategy in place and provide an annual review to ensure your money continues to earn a competitive rate and your product choices remain aligned to your evolving goals and circumstances.
Enter your current savings pot, your monthly saving amount, and slide the interest rate to generate a personalised projection across 1, 2, 5, 10, 15, 20, and 25 years — with full compound interest applied monthly.
Adjust the figures below to see how your savings could grow over time.
Your existing savings balance
Amount you plan to save each month
Adjust with the slider below
Moves in 0.25% increments. Interest rates shown are illustrative — actual rates vary by provider and are not guaranteed.
Blue area = interest earned on top of your contributions
| Year | Total Contributed | Interest Earned | Projected Value |
|---|---|---|---|
| 1 year | £8,600 | +£236 | £8,836 |
| 2 years | £12,200 | +£609 | £12,809 |
| 5 years | £23,000 | +£2,595 | £25,595 |
| 10 years | £41,000 | +£9,121 | £50,121 |
| 15 years | £59,000 | +£20,332 | £79,332 |
| 20 years | £77,000 | +£37,119 | £114,119 |
| 25 years | £95,000 | +£60,549 | £155,549 |
Over 25 years at 3.50%
£155,549
of which £60,549 is interest earned on top of your contributions
Figures are illustrative and assume a constant interest rate compounded monthly. They do not account for taxation, fees, inflation, or rate changes. Castle Stonebridge Limited is an Appointed Representative of Rosemount Financial Solutions (IFA) Limited, which is authorised and regulated by the Financial Conduct Authority. Rosemount Financial Solutions (IFA) Limited is entered on the Financial Services Register under reference 535515.
In the current tax year, every UK adult can save up to £20,000 across their ISA accounts. This allowance resets on 6th April each year and cannot be carried forward, so using it efficiently is important.
A Cash ISA offers capital security and is suitable for short-term goals or emergency funds. A Stocks & Shares ISA offers the potential for higher long-term returns but carries investment risk. Many clients benefit from holding both. We can help you decide the right split for your circumstances.
Interest rates vary significantly between providers and product types. As independent advisers, we are not tied to any one bank or building society — we search the market to find the most competitive rates for your specific needs and timeline.
Compound interest means you earn interest not just on your original capital, but on the interest you have already accrued. Over time, this snowball effect becomes powerful — particularly over 10 or more years. Our interactive Savings Growth Calculator on this page demonstrates exactly this effect with your own figures.
Risk Warning: The value of investments and the income from them can go down as well as up. Interest rates are not guaranteed and may change. Tax treatment depends on individual circumstances and is subject to change.
Book a free, no-obligation consultation with one of our independent advisers. We will review your current savings, identify any missed opportunities, and design a clear, tax-efficient strategy built around your goals.
Investment & Pensions Risk: Capital is at risk. The value of pensions and investments and the income they produce can fall as well as rise. You may get back less than you invested. Past performance is not a reliable indicator of future results.
