Savings goal calculator
The compound interest question asked backwards: name the target and the deadline, and get the monthly amount that reaches it, growth included.
Guide
How to use it
- Enter the target amount and when you need it.
- Add what you already have and a realistic annual rate.
- The tile gives the monthly amount; the chart shows contributions in gold and growth in blue doing the rest.
- Test the deadline: one extra year often shaves more off the monthly figure than a higher rate does.
Examples
Worked examples
£25,000 in 8 years, starting from £5,000 at 4.5%: about £145 a month, with growth contributing roughly £6,000 of the target.
£12,000 from zero at 4%: about £314 a month. Short horizons leave interest little room, the deposits carry it.
£20,000 today against a £25,000 target in 6 years at 4.5%: the needed contribution is zero, your existing pot grows past the line on its own.
Method
How it works
The target minus your starting pot's own projected growth is what contributions must supply. The annuity formula PMT = (T − P(1+i)ⁿ) × i ÷ ((1+i)ⁿ − 1) solves for the monthly amount, with i the monthly rate and n the number of months, contributions assumed at month end.
Constant rate, no fees, tax or inflation. Arithmetic, not advice, and nothing you enter leaves your browser.
FAQ
Frequently asked questions
How much do I need to save a month to reach a goal?
Enter the target, what you already have, the rate and the years: the tile answers directly. £25,000 in 8 years from £5,000 at 4.5% needs about £145 a month.
Does the calculation include growth on my contributions?
Yes, that is the point: each month's deposit earns from the moment it lands, so the required amount is lower than target divided by months.
What if my starting amount already covers the goal?
The needed contribution shows as zero and the tile explains that your existing balance alone grows past the target at the rate entered.
What rate should I assume?
For cash savings, a realistic account rate. For investments, long-run averages are commonly quoted but not guaranteed, and a lower assumption is the safer planning basis.
Should I adjust the target for inflation?
For goals years away, yes: a £25,000 goal in ten years buys less than today. Either raise the target or use a rate net of inflation for a real-terms answer.
Is this financial advice?
No. It solves an equation at a constant assumed rate with no fees or tax. Product decisions belong with a regulated adviser.
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