Savings Goal Calculator
Find out how much to save monthly to reach your savings goal.
What this calculator does
This calculator links a savings target to the monthly contribution that reaches it. Enter what you have saved, what you are aiming for, the return you expect, and the years available, and it returns your projected balance, the monthly amount required to hit the target exactly, and how far along you already are as a percentage.
The required-contribution figure is the useful one, because it converts a vague ambition into a number you can either commit to or reject. Most people find the timeline was the real constraint rather than their discipline, and adjusting years is a far cheaper fix than adjusting effort.
When to use it
Use it for any goal with a figure and a deadline attached — a house deposit, a wedding, replacing the car, a career break, private school fees, or simply a defined cash cushion. The structure is identical in each case.
Run it before committing to a timeline rather than afterwards. Moving a purchase from three years out to four is easy at the planning stage and painful eighteen months in. It also serves as a reality check on a target you have already set: if reaching it swallows 40 percent of your take-home pay, extend the deadline now rather than failing quietly later.
Understanding the inputs
Current savings should count only money genuinely allocated to this goal. Your emergency fund does not qualify, and neither does pension money you have no intention of touching.
Annual return should match where the money will actually sit. Short-horizon goals in a Cash ISA or fixed-rate bond support whatever AER is on offer; anything under three years should not assume equity returns. Years to goal is the hard deadline and the input worth flexing first. Monthly contribution should be what you can genuinely sustain — the figure that survives a bad month, not your best one.
How is this calculated?
PMT = (FV − PV × (1+r)^n) × r / ((1+r)^n − 1)
A worked example
Suppose you want £30,000 for a house deposit in four years and have £6,000 saved in a Cash ISA paying 4.5 percent. Your existing £6,000 grows to roughly £7,180 on its own, leaving about £22,820 to fund from contributions — around £435 a month.
If that is beyond reach, look at the levers rather than the discipline. Stretching the same £30,000 target to six years drops the required contribution to roughly £268 a month, a cut of nearly 40 percent for two more years of patience. A Lifetime ISA could also do heavy lifting here: £4,000 a year contributed attracts a £1,000 government bonus, worth £4,000 across the four years.
Limitations and assumptions
The calculator assumes a constant return and a level contribution every single month with nothing missed. Real saving is lumpier, and any rate much above 5 percent implies market exposure that can fall as readily as it rises. Past performance does not predict future returns, and no allowance is made for volatility.
It also ignores tax on interest and gains outside an ISA, and it does not inflate the target — so a goal tied to a rising price needs adjusting before you enter it. Treat the required contribution as a planning figure rather than a promise, and build in a margin instead of aiming to land exactly on the target.
Common Questions
- What does this calculator actually solve for?
- Two things at once. Given your current savings, a monthly contribution, a return rate, and a timeframe, it projects where you end up. It also works backwards from your target to show the monthly contribution needed to reach it exactly. Most people use the second figure and adjust the timeframe until it looks survivable.
- What return rate should I assume?
- It depends on the timeframe. Goals under three years belong in a Cash ISA, easy-access savings account, or fixed-rate bond, so use the quoted AER and treat it as reliable. Goals five years or further out can hold equities in a Stocks and Shares ISA, where 6 to 7 percent before inflation is a common planning figure rather than a guarantee.
- What if the required monthly amount is impossible?
- You have three levers: save more, extend the deadline, or lower the target. Extending is usually the most powerful, because both compounding and the extra months work in your favour. Pushing a four-year goal to six typically cuts the monthly requirement by around 35 percent, far more than most people expect.
- Should I use a Cash ISA or an ordinary savings account?
- Compare the AER first, then the tax. The Personal Savings Allowance shelters £1,000 of interest for basic rate taxpayers and £500 for higher rate, with nothing for additional rate. If your interest stays comfortably below that, a higher-paying ordinary account can beat a Cash ISA. Above it, the ISA wrapper usually wins.
- What about the Lifetime ISA for a house deposit?
- If the goal is a first home under £450,000 and you are aged 18 to 39, a Lifetime ISA adds a 25 percent government bonus on contributions of up to £4,000 a year — up to £1,000 free annually. Withdrawing for anything other than a first home or retirement after 60 triggers a 25 percent charge that costs you more than the bonus gave.
- Should I count my emergency fund toward a goal?
- No. An emergency fund is not savings you are building, it is insurance against having to raid the savings you are building. Keep three to six months of essential outgoings separate and untouched, then enter only what is genuinely earmarked for this goal.
- Where should short-term goal money sit?
- Somewhere the balance cannot fall. Easy-access savings, a Cash ISA, or a fixed-rate bond maturing just before you need the money. FSCS protection covers £85,000 per person per authorised firm. Equity markets have delivered negative three-year stretches often enough that a house deposit does not belong in one.
- Does this account for inflation?
- No. If your goal is a fixed sum such as a £20,000 wedding budget, that is fine. If it is something whose price moves — a house deposit, a car, school fees — inflate the target before entering it. A £30,000 deposit needed in five years at 3 percent inflation is really a £35,000 goal.
- What is a realistic savings rate to sustain?
- Most people can hold 10 to 20 percent of take-home pay indefinitely, with short bursts above 30 percent for a defined push. If the required contribution exceeds a quarter of your net income and the deadline is years away, the plan will probably break. Extend the deadline rather than abandon the goal.