Use the calculator
How this calculator works
A savings goal is easier to reach when you know how much you need to put away each month and how long it will take. This calculator projects how much a regular saving plan could grow. Enter what you have saved already, how much you plan to add each month, the interest rate and the number of years.
Each month your saving is added to the balance and one month of interest is applied. The result shows the projected balance at the end, how much of it you paid in, and how much came from interest. To find the monthly amount that reaches a particular target, try a few monthly amounts until the projected balance matches your goal.
For short goals of a year or two, the amount you pay in usually matters far more than the interest rate. Interest makes more difference as the period gets longer.
Worked examples
These results come from running this calculator.
Example 1: £500 already saved, £200 a month at 3% for 3 years
You pay in £7,700 in total, and the projected balance is £8,089.95, including £389.95 of interest.
Example 2: a two-year goal of about £7,500
Starting from nothing and saving £300 a month at 4% for 2 years gives a projected £7,507.81. You pay in £7,200 and interest adds £307.81. If £300 is too much, lowering it to £250 a month would need a longer timeframe to reach the same goal.
Example 3: a 0% interest check
Starting with £2,000 and saving £150 a month for 5 years at 0% gives exactly £11,000. Setting the rate to 0% is a useful check: it shows the minimum you would have if rates fall or you keep the money in a current account.
Savings allowances for 2026/27
| Allowance | Amount |
|---|---|
| Total ISA allowance | £20,000 |
| Personal Savings Allowance (basic / higher / additional rate) | £1,000 / £500 / £0 |
| Starting rate for savings | Up to £5,000, reduced by other income above the Personal Allowance |
Lifetime ISAs have their own limits and rules, set out on GOV.UK.
Assumptions and what this calculator does not cover
- It projects rather than solves: it shows where a monthly amount takes you, not the exact amount needed for a target. Adjust the monthly figure to find it.
- Fixed rate: interest rates on savings can change, and fixed-rate accounts may not allow regular deposits or withdrawals.
- Timing: deposits are assumed at the start of each month, compounded monthly.
- Not included: tax on interest, inflation, account limits, bonus rates that expire, and government bonuses such as the Lifetime ISA bonus.
- Investments: if you invest instead of saving cash, the value can fall as well as rise, so a fixed rate is only a rough guide.
Making a goal realistic
Before fixing a monthly amount, check that it fits your budget in a normal month, not just a good one. A smaller amount you can keep up is usually more effective than a larger one you have to stop after a few months.
It also helps to give each goal its own account or savings pot, so you can see your progress and avoid spending the money by accident. If you are saving for several things at once, run the calculator for each one separately and add up the monthly amounts to check the total is affordable.
For goals more than a couple of years away, re-run the calculator once or twice a year with your real balance and the current rate. If you are ahead of plan you could reduce the monthly amount or reach the goal sooner; if you are behind, a small increase early on is easier than a large one near the deadline.
Frequently asked questions
How do I find the monthly amount for my goal?
Enter your current savings, timeframe and expected rate, then change the monthly amount until the projected balance reaches your target. As a quick check without interest, divide the remaining amount by the number of months.
Should I use a cash ISA?
A cash ISA lets interest build tax-free within the £20,000 annual ISA allowance. Whether it suits your goal depends on the rate, access rules and whether your interest would be taxed anyway.
What about saving for a first home?
A Lifetime ISA can include a government bonus for eligible first-time buyers, but it has age limits, a maximum property price and a withdrawal charge for other uses. Read the GOV.UK rules before choosing one.
How does inflation affect my goal?
If the thing you are saving for rises in price, you may need more than today's cost. For longer goals, review the target each year against current prices.
What if I miss a month?
The projection assumes every payment is made. Missing payments will lower the result, so re-run the calculator with your actual balance to see whether you are still on track.
Sources
- GOV.UK: Individual Savings Accounts (ISAs)
- GOV.UK: Lifetime ISA
- GOV.UK: Tax on savings interest – how much tax-free interest you get
- Bank of England: Interest rates and Bank Rate
- ONS: Consumer price inflation, latest release
Rates for tax year 2026/27, last reviewed October 2026.
Results are estimates for planning, not financial or tax advice. See our terms and methodology.