Savings Goal Calculator
Enter your savings goal and find out how much you need to contribute each month to reach it within your chosen timeframe.
Results
Required monthly contribution
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Total contributed
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Interest/return earned
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Monthly contribution = (savings goal − initial capital × (1 + r)^n) ÷ [((1 + r)^n − 1) ÷ r], where r is the monthly return and n the number of months. At 0% return, the contribution is simply (goal − initial capital) ÷ n.
Your initial capital already reaches (or exceeds) your goal at this return and timeframe! You don't need to contribute anything more.
When should you use this calculator?
This calculator solves the reverse problem of compound interest: instead of projecting how much you'll have by saving a fixed amount, it calculates how much you need to contribute each month to reach a specific goal within a given timeframe.
Legal context in Spain
The return you use should match the type of product you're saving in: a savings account or deposit offers lower, more stable returns, while an index fund or a diversified portfolio can offer higher returns in exchange for more risk and volatility.
The sooner you start and the longer your timeframe, the lower the required monthly contribution, thanks to compound interest working on the capital you've already accumulated.
The result is a mathematical estimate based on a constant return, which varies in practice. It is not financial advice and doesn't guarantee the goal will be reached exactly within the projected timeframe.
Frequently asked questions
How is the required monthly savings amount calculated?
It starts from the savings goal and subtracts the future value of the initial capital already invested; the remainder is spread across monthly contributions that, at the given return, reach exactly the goal by the end of the timeframe.
What if my initial capital is already enough?
If the initial capital, grown at the given return over the timeframe, already reaches or exceeds the goal, the calculator shows that you don't need to contribute anything more.
What return should I use for a savings account versus investing?
A savings account or deposit typically offers 0-3% a year with very low risk. A diversified investment portfolio can return more over the long term, but with short-term value fluctuations.
Is this the same as the compound interest calculator?
Not quite. The compound interest calculator projects forward how much you'll have with a fixed contribution; this one solves it backwards, calculating the contribution needed to reach a specific goal.
How does inflation affect my savings goal?
If your goal is a fixed amount in today's money, inflation will reduce its future purchasing power. To account for it, you can increase the goal based on expected inflation, or use a return net of inflation.
What if I change my monthly contribution partway through?
This calculator's result assumes a constant contribution throughout the whole timeframe. If your actual contribution varies, the time needed to reach the goal will also differ from the initial estimate.