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Savings Goal Calculator

Give it the amount, the deadline and what you have already, and it works back to the monthly figure — then tells you honestly whether the amount you can actually manage gets you there.

Free to useNo sign-upRuns in your browserUK
The goal
£
A house deposit, a wedding, a car, a career break, a year of school fees — whatever the number actually is.
£
months
Rate and reality check
% AER
Set it to 0 to ignore interest and see the plain arithmetic.
£
Add this and the calculator will tell you whether the deadline holds, and if not, when you would actually get there.
You need to save
£0
How the target is reached
Already saved Your contributions Interest
Target
Already saved
You will pay in
Interest earned
Deadline
Per week
Per day
Interest does
Monthly rate used

What this calculator assumes

  • Interest is compounded monthly at the rate implied by the AER you enter — the twelfth root of one plus the AER, not the AER divided by twelve.
  • Contributions are assumed to arrive at the end of each month, which is the conservative treatment. Paying in at the start of the month earns slightly more.
  • The rate is held constant for the whole period. Easy-access rates move, so a long horizon makes the interest figure more of an illustration than a projection.
  • Interest is treated as tax-free, which holds inside an ISA and for most people under the personal savings allowance.
  • Inflation is not modelled. A target set today buys less in three years, which matters most for goals that are a long way out.
  • Money set aside for a goal within about five years belongs in cash rather than investments — this calculator assumes a savings account, not a stocks and shares return.
  • Nothing you type leaves your browser. There is no account, no sign-up and no data stored.

The monthly contribution is the standard future-value-of-an-annuity calculation, rearranged to solve for the payment. The full formula is shown below so you can check it.

A worked example

Suppose you need £15,000 in two years, you have £2,000 already, and the money sits in an account paying 4.00% AER.

£15,000 in 24 months from a £2,000 start
Target£15,000.00
Already saved£2,000.00
What the £2,000 grows to£2,163.20
Still needed from contributions£12,836.80
You pay in over 24 months£12,360.10
Interest on those contributions£476.70
Required each month£515.00

Interest does £639.90 of the work in total — the £163.20 earned on the opening balance plus £476.70 on the contributions as they accumulate. That is about 4.9% of the £13,000 gap you were trying to close, which is worth having but is not the thing that gets you there. Over two years, the contribution does almost all of it.

That balance shifts with the horizon. Stretch the same £2,000 start to a £50,000 goal over ten years and interest at the same rate contributes £9,520 — 19% of the total, rather than 4%. That is where the argument for investing rather than saving starts to bite. On a one-year goal it barely registers, and the only lever that matters is how much goes in.

The maths, so you can check it

The monthly amount is the future value of an annuity, rearranged to solve for the payment:

Required monthly contribution

i = (1 + AER)1/12 − 1
M = (FV − P × (1 + i)n) × i ÷ ((1 + i)n − 1)

FV is the target, P is what you have already, n is the number of months and i is the monthly rate. Where the AER is zero, this collapses to (FV − P) ÷ n.

The detail worth knowing is the first line. An AER of 4.00% is not 0.3333% a month, because monthly interest compounds. The correct monthly rate is the twelfth root of 1.04 minus 1, which is 0.3274%. Dividing by twelve overstates the return — not by much over two years, but enough to matter on a long horizon, and it is the most common error in homemade savings spreadsheets.

When the number comes back too high

Most people run this once and find the required amount is more than they can manage. There are only four levers, and it is worth being deliberate about which one you pull.

Enter what you can genuinely manage in the optional field and the calculator will tell you where that lands: how much you would have by the deadline, and when you would actually reach the target instead. A plan that admits it needs 31 months is more useful than one that pretends 24 will work.

One sequencing point. If you do not yet have an emergency fund, a goal with a deadline generally comes second — without a buffer, the first unexpected expense comes out of the goal. The emergency fund calculator sizes that, and the payday allocation calculator shows how both fit alongside your committed costs.

Frequently asked questions

How do I work out how much to save each month for a goal?▾
Take the target, subtract what your existing balance will grow to by the deadline, and divide the remainder by the future-value factor for the number of months involved. In practice: for £15,000 in 24 months from a £2,000 start at 4.00% AER, the existing balance grows to £2,163.20, leaving £12,836.80 to be funded by contributions, which works out at £515.00 a month. Ignoring interest entirely and dividing £13,000 by 24 gives £541.67, which is a reasonable rough answer if you want to be conservative.
How is AER converted to a monthly rate?▾
By taking the twelfth root of one plus the AER and subtracting one, not by dividing the AER by twelve. For 4.00% AER the correct monthly rate is 0.3274%, whereas dividing by twelve gives 0.3333%. AER already expresses the effect of compounding across a year, so dividing it by twelve double-counts. The difference is small over two years and meaningful over twenty.
Should I save or invest for my goal?▾
The conventional dividing line is about five years. Money needed sooner than that generally belongs in cash, because investments can fall sharply and you would have no time to recover before you need the money. Beyond five years the argument shifts, because inflation erodes cash while a diversified investment has time to ride out a downturn. This calculator assumes a savings account throughout. Whether investing suits your circumstances is a question for a qualified adviser.
Where should I keep money for a savings goal?▾
For a goal one to five years out, an instant-access or fixed-term cash savings account, ideally within an ISA so the interest is tax-free. A fixed-term bond usually pays more but locks the money up, which suits a goal with a firm date and no chance of needing the money early. If the goal is a first home, a Lifetime ISA adds a 25% government bonus on up to £4,000 a year, though it carries withdrawal penalties and property price limits that are worth reading carefully before committing.
What if I cannot afford the monthly amount?▾
Enter what you can genuinely manage in the optional field and the calculator will show you two things: the balance you would actually have on the deadline, and the date you would really hit the target. From there the levers are the deadline, the target itself, the amount going in, and the interest rate — in roughly that order of usefulness. Moving a deadline out by a third cuts the monthly requirement by about a third; improving the rate barely moves it on a short horizon.
Does this account for inflation?▾
No. Every figure is in today's pounds, and the target you enter is treated as a fixed cash amount. For a goal a year or two away that is a fair approximation. For something a decade out it is not, because the thing you are saving for will probably cost more by then. If you are planning a long-horizon goal, it is worth revisiting the target periodically rather than setting it once.

Other calculators

🛡
Emergency Fund Calculator
The buffer that usually comes before a goal with a deadline.
💵
Payday Allocation Calculator
How much is genuinely spare each month once committed costs are out.
🏠
Mortgage Affordability Calculator
Saving a deposit? See what that deposit would let you borrow.

Goals are easy to set and easy to quietly abandon

The month a goal stops getting funded is rarely a decision — it is usually an expensive month that nobody noticed. earmarkIQ tracks goals against your actual balances, shows whether you are ahead or behind the line you set, and folds the contribution into your payday allocation so it comes out before the spending rather than after.

See goal tracking → How payday allocation works → Get the app →