Savings Calculator
Have a savings goal and want to know how much to set aside each month to reach it? Enter the target, what you have already saved, the time frame and an interest rate. The calculator shows the monthly contribution you need and how much of it comes from interest.
Use a realistic annual interest rate for the product you intend to use (for example, a term deposit or Savings Certificates). If unsure, 2% is a prudent starting point.
Year-by-year growth
| Year | Interest | Balance |
|---|---|---|
| 1 | €53 | €4,650 |
| 2 | €180 | €8,373 |
| 3 | €382 | €12,171 |
| 4 | €661 | €16,046 |
| 5 | €1,018 | €20,000 |
Educational estimate, not financial advice. Interest is not guaranteed and may vary.
What this calculator does
Unlike the compound-interest calculator (which starts from a monthly amount and shows what you will end with), this one solves the problem the other way around: it starts from the goal you want to reach and works out the monthly contribution needed to get there within your time frame.
The formula
With monthly compounding: PMT = (Goal − Initial·(1+i)^n)·i ÷ ((1+i)^n − 1), where i is the annual rate divided by 12 and n is the number of months. If the rate is 0%, it simplifies to (Goal − Initial) ÷ months. If what you already have grows to the goal on its own, the required contribution is zero.
What moves the result most
Time is the most powerful factor: the earlier you start, the smaller the monthly contribution needed, because there are more months to add up and more time for compound interest to work. The interest rate helps, but regular saving effort is what counts most.
Worked example
To reach €20,000 in 5 years, starting from €1,000 already saved and at a 2% annual rate, you need to save about €299.69 per month. In total you contribute around €18,981 and interest adds over €1,000, which gets you to the goal.
Frequently asked questions
How is this different from the compound interest calculator?
Is the monthly contribution fixed for the whole period?
What if I already have enough saved to reach the goal?
Are the results guaranteed?
Related calculators & reading
Sources
- Todos Contam: Portal de educação financeira — Banco de Portugal
Author: Thorben Rasmus Idel · Reviewed by: Nahar Geva · Last reviewed: 2026-05-31