> calculator interest
Interest calculator and savings plan
Work out what becomes of your savings: with a starting amount, a monthly saving, an interest rate and a term. You see the final amount, your deposits and the interest earned including compound interest, and year by year as a table if you like. A calculation aid, not financial advice.
How it is calculated: interest is credited once a year and from then on earns interest too. Payments made during the current year earn interest pro rata by month: a payment at the start of the month earns 6.5 months of interest on average, one at the end of the month 5.5.
View year by year
| Year | Deposits | Interest | Balance at year end |
|---|---|---|---|
| Total | – | – | – |
Related: Loan and repayment plan · Percentage calculator · Retirement start (German) · VAT
The calculation runs only on your device.
How it works
- 01Type the starting amount and the monthly saving with a decimal point: 1,000.00. One of the two may stay empty.
- 02Enter the interest rate per year and the term in whole years.
- 03The final amount and the interest earned appear at once. “View year by year” shows the table.
Calculating interest with compound interest. Interest is credited once a year and then earns interest as well. For a one-time investment: final amount = starting amount × (1 + rate ÷ 100) to the power of the years. Payments made during the current year count pro rata by month.
Example 1: one-time investment. €10,000 at 3% for 10 years, without a monthly saving: 10,000 × 1.03 to the power of 10 = €13,439.16. Of that, €3,439.16 is interest. Without compound interest it would be only €3,000.
Example 2: savings plan with a starting amount. €1,000 to start and €100 a month at 3% for 10 years, paid at the start of the month: you pay in €13,000, get €2,324.12 in interest and end up with €15,324.12.
Example 3: saving for a child. €50 a month at 2% for 18 years, without a starting amount: paid in €10,800, interest €2,186.57, final amount €12,986.57.
The term goes up to 80 years. The interest rate stays the same over the whole time in the calculation. In reality it changes, and in Germany interest income above the saver's allowance (Sparerpauschbetrag) is subject to the flat tax (Abgeltungsteuer). This tool does not include either.