Savings Goal Calculator
Find the monthly contribution needed to reach a savings goal by a target date.
Cómo funciona
This calculator works backward from a savings target: given a goal amount, what you already have saved, a timeframe, and an expected rate of return, it finds the level monthly contribution needed to close the gap between where you are now and where you want to be.
The calculation first projects your current savings forward with compound growth over the full timeframe, using the expected annual return compounded monthly — this shows what your existing savings alone will grow into, without any further contributions.
It then finds the remaining gap between that projected value and your goal, and solves for the level monthly contribution (which also compounds, since each contribution starts earning its own returns from the moment it's added) that would close exactly that gap by the target date.
For example, reaching a $20,000 goal in 5 years starting from $2,000 saved, at a 4% expected annual return, requires contributing roughly $265 per month — a figure that accounts for the compound growth of both the initial $2,000 and every monthly contribution along the way.
The required monthly contribution is highly sensitive to the assumed rate of return and timeframe: a longer timeframe or a higher assumed return both reduce the monthly amount needed, since more time or a higher return means compounding does more of the work — which is exactly why starting a savings goal earlier, even with smaller contributions, tends to be far easier than starting later and needing to catch up.
This calculator assumes a level (constant) monthly contribution throughout the entire period — in reality, many people's ability to save changes over time (getting a raise, paying off other debt), so revisiting the calculation periodically as circumstances change is more realistic than committing to one fixed number years in advance.
Choosing an appropriate expected rate of return matters a great deal for the accuracy of the result — a savings goal funded in a low-yield savings account should assume a much lower return than one invested in a diversified stock portfolio, and using an unrealistically optimistic rate risks under-saving relative to what will actually be needed to hit the goal.
What if I already have enough saved?
If your current savings alone will grow to meet the goal, the required monthly contribution shows as zero.
How does the expected rate of return affect the required contribution?
A higher assumed return lowers the required monthly contribution, since more of the goal is reached through compound growth rather than new money — but assuming too high a return risks underestimating what you'll actually need to save.
What's a realistic rate of return to assume for this calculator?
This depends on where the money will actually be invested — a savings account, bonds, and stocks all carry very different typical returns and risk levels; there's no single universally correct figure to assume.
Does a longer timeframe always mean a smaller monthly contribution?
Generally yes — more time means more compounding periods, which typically reduces the required monthly amount to reach the same goal, all else equal.
Should I revisit this calculation over time?
Yes — as your income, expenses, or the timeframe change, recalculating periodically keeps the target contribution realistic rather than relying on an assumption made years earlier.
Does this calculator account for taxes on investment growth?
No — it shows nominal growth before any taxes that might apply depending on the account type (taxable, tax-deferred, or tax-free) your savings are actually held in.
What if I can't afford the calculated monthly contribution?
Consider adjusting the target date further out, lowering the goal amount, or exploring investment options with different risk/return profiles — the calculator can be rerun with adjusted inputs to see how each change affects the required contribution.
Is this the same calculation as the Compound Interest Calculator?
Related but solving the opposite direction — Compound Interest projects forward from known contributions to a final amount, while this tool works backward from a target final amount to find the required contribution.
Why does the assumed rate of return matter so much for accuracy?
An overly optimistic assumed return understates the monthly contribution actually needed, risking a shortfall at the target date — matching the assumption to where the money is genuinely invested gives a more reliable number.
Should I use a conservative or optimistic return assumption?
A conservative assumption is generally safer for planning purposes, since it's better to save slightly more than needed than to fall short of an important goal due to an overly rosy return estimate.