Savings goal calculator 2026
A savings goal is reached through regular monthly contributions plus compound growth on the balance. This calculator works back from a target amount, existing savings, an annual return and a time horizon to the constant monthly saving required.
- Required monthly saving€374.13
- Target€100,000.00
- Total saved€67,342.85
- Interest earned€32,657.15
Over time
Illustration only, not financial advice. Assumes a constant rate and regular intervals; real products vary. Verify with a professional.
The annuity formula behind the monthly figure
The calculator works backwards from a target amount to find the constant monthly contribution that reaches it. It first turns the annual return into a monthly rate i (annual return divided by 100, then by 12) and the time horizon into a number of months n (years times 12, with years rounded to a whole number between 1 and 100). Your already-saved amount grows on its own to initial times (1+i) to the power n by the end of the period. The required monthly payment closes the gap between that grown balance and the target: monthly payment = (target minus initial times (1+i)^n) times i, divided by ((1+i)^n minus 1). If the return is set to 0%, this simplifies to (target minus initial) divided by n. Contributions are assumed to land at the end of each month, so the first payment does not earn interest during its own month. All displayed euro figures are rounded to two decimals.
Reaching EUR 100,000 from zero in 15 years
Set the target amount to EUR 100,000, already saved to EUR 0, the annual return to 5% and the years to 15 -- the same defaults the calculator opens with -- and it returns a required monthly saving of EUR 374.13. Over 180 months that adds up to EUR 67,342.85 paid in from your own pocket, with the remaining EUR 32,657.15 of the EUR 100,000 target coming from compounding at 5% a year, applied monthly. Lower the return to 2.5% with everything else unchanged and the required monthly payment rises to EUR 458.46, because a smaller share of the goal is being carried by growth rather than contributions. You can reproduce both figures directly in the widget above by moving the annual-return slider and reading the required monthly saving and interest earned rows.
What the calculation takes as given
The formula assumes the annual return you enter applies evenly, month after month, for the entire horizon -- it does not vary by year, dip in a bad year or rise in a good one. It assumes the same monthly contribution throughout, paid at the end of each month, with no missed or extra payments and no change in the amount as your income changes. The already-saved figure is treated as a single lump sum invested from day one at the same rate as future contributions. No account fees, platform charges, transaction costs or taxes on interest or gains are subtracted anywhere in the calculation -- the target, the interest earned figure and the required monthly saving are all pre-cost, pre-tax numbers.
Where the estimate stops matching reality
Real savings rarely grow at one constant rate: interest rates move, markets rise and fall, and a return that averages out over 15 years can still include years of loss. The calculator has no way to reflect that path, only a single flat assumption, so the required monthly figure it shows is not a guarantee that the target will actually be reached on schedule. It also leaves out taxes on interest or investment gains, which reduce what you keep depending on where you live and what account you use; account or advisory fees, which reduce the effective return; inflation, which erodes what the target amount can buy by the time you reach it; and your ability to keep contributing the same amount every month for the full horizon.
Using the required-monthly figure as a planning tool
Treat the required monthly figure as a planning estimate, not a promise. It is most useful for comparing scenarios against each other -- see how much the monthly amount drops if you extend the horizon by a few years, start with a larger already-saved balance, or assume a more conservative return -- rather than as a single number to commit to blindly. It is also a reasonable way to sanity-check a savings plan or product someone else has proposed to you: enter the same target, timeframe and stated return and see whether the monthly figure it produces is in the same range. It is not personalised advice and does not account for your tax situation, other goals or risk tolerance.
FAQ
Is the annual return compounded monthly or yearly?
Monthly. The calculator converts the annual return you enter into a monthly rate by dividing it by 12, then applies that rate to the balance every month for the full number of months in the horizon. This is a simplification of how real interest or investment returns compound, but it is a common convention for comparing savings scenarios and matches how the accompanying chart builds up year by year.
What happens if I already have more saved than my target?
The required monthly saving cannot go below zero, so once your already-saved amount is projected to grow past the target on its own, the calculator shows EUR 0 rather than a negative number. It does not calculate a withdrawal amount or tell you what to do with the surplus -- it only ever solves for how much more, if anything, needs to be added.
Why does moving the years slider by one year change the result more than expected?
The years input is rounded to a whole number and limited to between 1 and 100 before it is turned into a month count, so every step on the slider changes the horizon by a full 12 months at once. There is no way to enter a fractional number of years such as 4.5, which is why the required monthly figure can jump rather than shift smoothly.
Does the first monthly payment start earning interest straight away?
No. The calculator assumes each contribution is paid at the end of its month, so the payment made in month one only starts earning the monthly return from month two onward. This end-of-month convention is why the total interest earned is slightly lower than it would be if contributions were assumed to arrive at the start of each month instead.