Finance
Savings goal calculator
Run the arithmetic the other way round: name the target and the date, and find out what it costs per month.
Working backwards from the target
First the calculator grows whatever you already have to the target date. Whatever gap remains has to be filled by deposits, and the annuity formula converts that gap into a monthly figure that accounts for the growth each deposit earns along the way.
If the rate is zero the formula collapses to gap divided by months, which is exactly what you would expect from a jar under the bed.
Match the account to the deadline
The expected return you enter should reflect where the money will actually sit, and that depends on when you need it.
- Under three years — a high-yield savings account, money market fund or short-term certificate. Capital preservation matters more than growth, because you have no time to recover from a fall.
- Three to seven years — a conservative mix. Some equity exposure is defensible, but a 30% drawdown eighteen months before a house purchase is a real risk, not a theoretical one.
- Beyond seven years — a diversified equity portfolio becomes reasonable, with the usual caveat that the return is an assumption and not a promise.
Automate the transfer, not the intention
A standing order on payday is more effective than a plan to save what is left at month end, for the straightforward reason that there is rarely anything left at month end. Treating the deposit as a fixed bill rather than a residual is the single change most likely to make the number above happen.
If the required amount looks impossible, the three levers are the target, the deadline and the deposit. Extending the deadline is usually the least painful — the monthly figure falls faster than proportionally, because the extra months earn returns too.
Build the emergency fund first
Saving toward a goal while carrying no cash buffer means the first unexpected expense either raids the goal or goes on a credit card at 22%. Three to six months of essential expenses in an instant-access account is the usual guidance, and it protects every other plan you have.
Common questions
What return should I assume for a savings goal?
Use the actual rate on the account if it is cash. For invested money, a modest assumption is safer here than an optimistic one — undershooting a target is worse than arriving early. Many people run the calculation twice, once at a realistic rate and once at zero, to see how much of the plan depends on returns.
Should I save or pay off debt first?
Compare the interest rates. Debt at 20% is a guaranteed 20% return if you clear it, which almost nothing else matches. The usual exception is keeping a small emergency buffer first, so that a surprise expense does not put the debt straight back on the card.
How do I account for inflation in a long-term goal?
Either raise the target to reflect what the thing will cost by then, or enter your return minus expected inflation so the answer comes out in today’s money. Do one or the other, not both.