CALCULARS / CONTEXT ACCOUNTS
Composite interest calculator.
Your bill, step by step.
Simulate compound interest with initial capital and monthly contributions. You can reinvest or withdraw interest, compare time frames and explore an income target. The subtractions from my Mintos extracts serve as a historical reference for fees and withholdings.
after the fees
and withholdings shown
CAPITAL, CONTRIBUTIONS AND TIME
Composite interest with monthly contributions
Start with an amount, move the contributions and give it time. You can reinvest or withdraw the interest, and see how much the account changes.
IN THE ACCOUNT OF THE 10 YEARS-OLD CAPE
- What you contributed
- 29,000.00 €
- Reinvested interest, after subtraction
- 16,625.09 €
5,000 initial € + 200 € at the end of each month. Nominal gross rate assumed: 8 % per year. Monthly reinvestment after historical subtractions.
The curve is a scenario with a constant rate. The capital shown can continue to be invested; it does not amount to cash available to withdraw.
To reach 50,000.00 € in the account. It is beyond the ten years shown in the chart; we maintain the same assumptions up to a maximum of fifty years.
Reinvesting payments
45,625.09 €in the account at the end of the periodWithdrawing payments
29,000.00 €in the account, more 12,381.39 € interest withdrawn during the periodThe two options are based on the same capital and the same contributions. Retired interests are shown separately and are not reinvested.
See evolution year by year
| Time frame | Account | Supported | Reinvested interest |
|---|---|---|---|
| Year 1 | 7,861.12 € | 7,400.00 € | 461.12 € |
| Year 2 | 10,939.04 € | 9,800.00 € | 1,139.04 € |
| Year 3 | 14,250.18 € | 12,200.00 € | 2,050.18 € |
| Year 4 | 17,812.21 € | 14,600.00 € | 3,212.21 € |
| Year 5 | 21,644.16 € | 17,000.00 € | 4,644.16 € |
| Year 6 | 25,766.46 € | 19,400.00 € | 6,366.46 € |
| Year 7 | 30,201.13 € | 21,800.00 € | 8,401.13 € |
| Year 8 | 34,971.82 € | 24,200.00 € | 10,771.82 € |
| Year 9 | 40,104.01 € | 26,600.00 € | 13,504.01 € |
| Year 10 | 45,625.09 € | 29,000.00 € | 16,625.09 € |
How We Calculate Composite Interest
We calculate each month with the capital of that moment. Gross interest of the month is capital × annual nominal rate / 12 × (1 − reduction of payments). To that amount we subtract the historical proportions of fees and withholdings. If you reinvest, what remains is added to the account; if you withdraw the payments, we accumulate it separately.
The contribution comes at the beginning or end of each month, as you choose. The objectives are sought from the beginning and are considered reached at the first monthly closure that reaches that capital, up to a maximum of fifty years, using the same scenario. The objective is capital in the account; the interests withdrawn do not add to that capital.
- Gross interest accumulated in the chosen scenario
- 18,153.95 €
- Cumulative proportional fees
- 632.56 €
- Cumulative proportional withholdings
- 896.31 €
We apply the proportions of my entire twelve months as an approximation, without rounding the intermediate balances. Tariffs, payments and taxation can change over the period. withholding is not the definitive tax. Capital losses, inflation, periods without investing or changes of type are not simulated.
The percentage is nominal: a nominal gross 8 % is not an annual cash 8 % when you reinvest monthly. The result is illustrative and does not guarantee that your account will grow like this. See the period and historical subtractions used.
FROM INTERESTS TO RESTAURANTS
To collect € 100 is not to keep € 100.
Enter an amount of gross interest. We will apply the proportion of fees and withholdings that appears in my last twelve full months.
Reference: November 2025 to October 2026.
See the figures and method ↓
AFTER THE RESTS SHOWED
- Gross interest
- 100.00 €
- fees shown
- −3.48 €
- withholdings shown
- −4.94 €
This subtraction is not the total return or cash available to withdraw. withholdings are not your final tax either.
POWER IT TO AN IDEA
And to get 100 € per month?
Choose a target and an assumed annual gross rate. The calculation retains the cost and withholding ratios of the historical. You can also prove what happens if the payments are lower.
THE CAPITAL THAT WOULD REQUIRE THIS SUPPOSED
To obtain 100.00 € per month after these subtractions, with an assumed gross annual rate of 8 %.
- Gross interest per month on stage
- 109.20 €
- Proportional Committees
- −3.80 €
- Proportional withholdings
- −5.39 €
It involves uniform payments and full capital working at the indicated rate, without reinvestment. It does not include capital losses, inflation or the rest of your taxation. A monthly goal does not guarantee that you can withdraw that amount every month.
With the same assumed type and the same subtractions:
Each column applies its own reduction to the initial scenario. Reductions do not accumulate.
WHAT HAPPENED IN MY ACCOUNT
Months also have ups and downs.
In these twelve months, the interest subtraction less costs and withholdings was from 195.77 € to 294.22 €. May of 2026 did not look like December of 2025. You can open each balance sheet and read what happened.
My payments, month by month
Gross interestAfter fees and withholdings shown
October 2026
282.68 €after shown deductions- Interest
- 307.33 €
- Fees
- −9.30 €
- Tax withholdings
- −15.35 €
Amounts from my Mintos Transaction Summary. Partial periods excluded: November 2026, through day 2. These amounts are not adjusted for the capital invested in each month.
See the twelve months and their exact amounts
| Month | Gross interest | Fees | Tax withholdings | After subtractions |
|---|---|---|---|---|
| November 2025 | 293.43 € | 9.43 € | 14.18 € | 269.82 € |
| December 2025 | 318.91 € | 9.11 € | 15.58 € | 294.22 € |
| January 2026 | 289.40 € | 9.61 € | 13.90 € | 265.89 € |
| February 2026 | 272.17 € | 10.10 € | 13.49 € | 248.58 € |
| March 2026 | 272.58 € | 9.14 € | 13.57 € | 249.87 € |
| April 2026 | 284.17 € | 10.02 € | 13.90 € | 260.25 € |
| May 2026 | 216.43 € | 9.84 € | 10.82 € | 195.77 € |
| June 2026 | 295.01 € | 10.14 € | 14.69 € | 270.18 € |
| July 2026 | 261.73 € | 9.76 € | 12.99 € | 238.98 € |
| August 2026 | 264.98 € | 10.07 € | 13.25 € | 241.66 € |
| September 2026 | 262.74 € | 9.82 € | 13.13 € | 239.79 € |
| October 2026 | 307.33 € | 9.30 € | 15.35 € | 282.68 € |
WHERE THE CIRFS GO OUT
The method, in sight.
I used the twelve most recent complete months in the archive: November 2025 to October 2026. They total 3,338.88 € in interest charged, 116.34 € in fees shown and 164.85 € in withholdings.
We divide the fees and the total withholdings between the total interest. So we get what was subtracted for each 100 € charged: 3.48 € and 4.94 €, respectively. We use the unrounded proportions; the results are shown to the cent.
It is an approximation based on my extracts. Real fees may depend on capital, product and current rates, and withholding depends on fiscal circumstances. Keeping these proportions for another amount does not reproduce Mintos' tariff.
The formulae and limits of the calculation
Interest balance: gross × (1 − total fees / total interest − total withholdings / total interest).
Objective capital: monthly target × 12 / [annual gross rate / 100 × (1 − reduction of payments / 100) × proportion remaining after subtractions]. Model a year with uniform and non-reinvestment charges.
Contributions and principal returns are not counted as interest. The amounts of capital arrears are not converted into a probability of delay or loss. The history collects what is collected, not everything earned or what is still outstanding.
To calculate my annual profitability rigorously lack the portfolio valuations and the dates and amounts of all relevant flows. Splitting the interest of the year between today’s balance would give a misleading figure.
Statements before January 2025 are also missing. This tool uses twelve closed months; it does not measure my account’s complete result or predict someone else’s.