Question 1

Is my data private?

Accepted Answer

Yes. All calculations happen entirely in your browser. No personal data or inputs are sent to or stored on any server. Your saved inputs are stored in your browser's local storage and can be cleared at any time.

Question 2

Is this financial advice?

Accepted Answer

No. This calculator is for informational and educational purposes only. It does not constitute financial advice. Interest rates used are illustrative examples. Always consult a qualified, independent financial adviser before making financial decisions.

Question 3

How accurate are the results?

Accepted Answer

The calculator uses standard compound interest formulas and produces mathematically accurate projections based on the inputs you provide. However, results are estimates because real-world factors — rate changes, tax, fees, and inflation — can affect actual outcomes. Use the results as a planning guide, not a guarantee.

Question 4

When was this calculator last updated?

Accepted Answer

The calculator and all content pages were last reviewed and updated in January 2025. Example interest rates are checked periodically but may not reflect current market conditions. Always verify rates with your bank or building society.

Question 5

Can I export my results?

Accepted Answer

Yes. After calculating your results, click the 'Export PDF' button to download a clean, print-friendly PDF containing your inputs, results summary, year-by-year breakdown table, and a timestamp. The PDF does not include any advertisements.

Question 6

How do I report an error or bug?

Accepted Answer

Please use our contact form to report any errors, bugs, or inaccurate content. Select 'Report a bug or error' from the subject dropdown. We review all reports and aim to fix issues promptly.

Question 7

What is the difference between APR and APY?

Accepted Answer

APR (Annual Percentage Rate) is the simple annual rate without accounting for compounding. APY (Annual Percentage Yield), also known as AER in the UK, includes the effect of compounding and shows your actual effective return. Our calculator uses APY for more accurate results. Read our guide on APY vs APR for a full explanation.

Question 8

Which compounding frequency should I choose?

Accepted Answer

Check your savings account terms to find out how often your bank compounds interest. Most UK easy-access accounts compound daily or monthly. Fixed-rate bonds may compound annually. If unsure, monthly compounding is a reasonable default for planning purposes.

Question 9

Does the calculator account for tax?

Accepted Answer

No. The calculator shows gross (pre-tax) interest. In the UK, the Personal Savings Allowance lets basic rate taxpayers earn £1,000 in interest tax-free, and higher rate taxpayers £500. Interest above your allowance is taxed at your marginal rate. Cash ISA interest is always tax-free.

Question 10

Can I use this for investment returns?

Accepted Answer

This calculator is designed for savings accounts with fixed or guaranteed interest rates. Investment returns are variable and can be negative, so this tool is not suitable for modelling stock market investments, funds, or other variable-return assets. It works well for cash savings, bonds, and ISAs with stated rates.

Question 11

How does the Goal mode work?

Accepted Answer

Goal mode works backwards from your target. Enter the amount you want to save, your starting balance, interest rate, and timeline. The calculator uses binary search to find the exact monthly contribution needed to reach your target, accounting for compound interest along the way.

Question 12

What does the Withdrawal mode show?

Accepted Answer

Withdrawal mode calculates how long your savings will last if you withdraw a fixed amount each month while the remaining balance continues earning interest. It is useful for retirement planning or understanding the sustainability of drawing down a savings fund.

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