How the calculator works
It starts from what you've already saved and adds your monthly amount at the end of each month. Interest is added monthly at a twelfth of the yearly rate, on everything saved so far — including interest you've already earned.
To find the monthly amount, it works out what your current savings will grow to by the deadline, then the deposit that covers the rest, rounded up to the nearest pound. To find the time, it steps forward month by month until the balance reaches the goal.
An example
Say you want a £6,000 emergency fund in two years, starting from nothing. Without interest that's £250 a month. In an easy-access account paying 4%, about £241 a month gets you there, because interest covers the rest. Give yourself three years and it drops to about £157.
Making the goal stick
Set up a standing order for payday, so the saving happens before you can spend it. Keep the money in a separate account, ideally one that pays interest, and check in every few months. If your pay or the rate changes, rerun the numbers and adjust the amount rather than giving up on the goal.
What the calculator leaves out
Savings rates change, so treat the result as a plan, not a promise. It ignores tax: interest above your Personal Savings Allowance is taxable unless the money sits in an ISA. It also ignores inflation — if your goal is a price that will rise, like a house deposit, aim a little higher.
Common questions
How much should I save each month?
Work back from the goal: divide what's left by the months you have, then let interest trim it a little. If the answer doesn't fit your budget, give yourself more time rather than skipping months — a smaller amount you keep up beats a bigger one you abandon.
How big should an emergency fund be?
A common rule of thumb is three to six months of essential costs: rent, bills, food and travel. Start with one month as a first goal, then build from there.
Where should I keep money I'm saving for a goal?
For goals a few years away, an easy-access savings account or a cash ISA keeps the money safe and earning interest. Investing suits goals five or more years away, because prices can fall in the short term.
Does the calculator include interest?
Yes. Interest is added monthly at the rate you enter. Set the rate to 0 to see the figure without it.