Four monthly amounts, each with its own horizon, all in a global index fund with 0.14% ongoing costs and a 6% a year return before costs. Real returns go up and down and can be negative; the 6% is a calculation example, not a forecast.
The four examples side by side
| Per month | Start | Horizon | Total deposited | Net balance | Fee erosion | Fees as % of gain |
|---|---|---|---|---|---|---|
| €100 | €0 | 40 years | €48,000 | €191,745 | €7,405 | 4.9% |
| €250 | €0 | 30 years | €90,000 | €244,508 | €6,621 | 4.11% |
| €500 | €5,000 | 25 years | €155,000 | €360,688 | €8,134 | 3.8% |
| €1,000 | €0 | 25 years | €300,000 | €678,254 | €14,740 | 3.75% |
€100 a month, 40 years
The smallest amount gets the longest horizon, 40 years, to show what time does when each deposit is small.
| Assumptions | Value |
|---|---|
| Starting amount | €0 |
| Monthly contribution | €100 |
| Horizon | 40 years |
| Return before costs | 6% a year |
| Fund costs (TER) | 0.14% a year |
| Result after 40 years | Amount |
|---|---|
| Total deposited | €48,000 |
| Gross balance | €199,149 |
| Net balance | €191,745 |
| Fee erosion | €7,405 |
| Net gain | €143,745 |
| Fees as % of gain | 4.9% |
| Year | Deposited | Balance after costs | Growth |
|---|---|---|---|
| 5 | €6,000 | €6,952 | €952 |
| 10 | €12,000 | €16,264 | €4,264 |
| 15 | €18,000 | €28,737 | €10,737 |
| 20 | €24,000 | €45,445 | €21,445 |
| 25 | €30,000 | €67,825 | €37,825 |
| 30 | €36,000 | €97,803 | €61,803 |
| 35 | €42,000 | €137,958 | €95,958 |
| 40 | €48,000 | €191,745 | €143,745 |
Starting five years later and adding the same amount for 35 years ends at €137,958 instead of €191,745, with €42,000 deposited instead of €48,000. That leaves out €6,000 of deposits and lowers the final balance by €53,787, because the skipped deposits had the longest to grow.
€250 a month, 30 years
Thirty years is a common working-life stretch for a first savings plan; the amount is mid-range.
| Assumptions | Value |
|---|---|
| Starting amount | €0 |
| Monthly contribution | €250 |
| Horizon | 30 years |
| Return before costs | 6% a year |
| Fund costs (TER) | 0.14% a year |
| Result after 30 years | Amount |
|---|---|
| Total deposited | €90,000 |
| Gross balance | €251,129 |
| Net balance | €244,508 |
| Fee erosion | €6,621 |
| Net gain | €154,508 |
| Fees as % of gain | 4.11% |
| Year | Deposited | Balance after costs | Growth |
|---|---|---|---|
| 5 | €15,000 | €17,380 | €2,380 |
| 10 | €30,000 | €40,660 | €10,660 |
| 15 | €45,000 | €71,843 | €26,843 |
| 20 | €60,000 | €113,613 | €53,613 |
| 25 | €75,000 | €169,563 | €94,563 |
| 30 | €90,000 | €244,508 | €154,508 |
Starting five years later and adding the same amount for 25 years ends at €169,563 instead of €244,508, with €75,000 deposited instead of €90,000. That leaves out €15,000 of deposits and lowers the final balance by €74,945, because the skipped deposits had the longest to grow.
€500 a month, 25 years
This is the calculator’s default example: €5,000 to start and €500 a month for 25 years.
| Assumptions | Value |
|---|---|
| Starting amount | €5,000 |
| Monthly contribution | €500 |
| Horizon | 25 years |
| Return before costs | 6% a year |
| Fund costs (TER) | 0.14% a year |
| Result after 25 years | Amount |
|---|---|
| Total deposited | €155,000 |
| Gross balance | €368,822 |
| Net balance | €360,688 |
| Fee erosion | €8,134 |
| Net gain | €205,688 |
| Fees as % of gain | 3.8% |
| Year | Deposited | Balance after costs | Growth |
|---|---|---|---|
| 5 | €35,000 | €41,457 | €6,457 |
| 10 | €65,000 | €90,291 | €25,291 |
| 15 | €95,000 | €155,704 | €60,704 |
| 20 | €125,000 | €243,323 | €118,323 |
| 25 | €155,000 | €360,688 | €205,688 |
Starting five years later and adding the same amount for 20 years ends at €243,323 instead of €360,688, with €125,000 deposited instead of €155,000. That leaves out €30,000 of deposits and lowers the final balance by €117,365, because the skipped deposits had the longest to grow.
€1,000 a month, 25 years
The largest amount over 25 years shows how fee erosion grows in euros even though the percentage barely moves.
| Assumptions | Value |
|---|---|
| Starting amount | €0 |
| Monthly contribution | €1,000 |
| Horizon | 25 years |
| Return before costs | 6% a year |
| Fund costs (TER) | 0.14% a year |
| Result after 25 years | Amount |
|---|---|
| Total deposited | €300,000 |
| Gross balance | €692,994 |
| Net balance | €678,254 |
| Fee erosion | €14,740 |
| Net gain | €378,254 |
| Fees as % of gain | 3.75% |
| Year | Deposited | Balance after costs | Growth |
|---|---|---|---|
| 5 | €60,000 | €69,520 | €9,520 |
| 10 | €120,000 | €162,640 | €42,640 |
| 15 | €180,000 | €287,374 | €107,374 |
| 20 | €240,000 | €454,453 | €214,453 |
| 25 | €300,000 | €678,254 | €378,254 |
Starting five years later and adding the same amount for 20 years ends at €454,453 instead of €678,254, with €240,000 deposited instead of €300,000. That leaves out €60,000 of deposits and lowers the final balance by €223,801, because the skipped deposits had the longest to grow.
The same 25 years for every amount
| Per month | Total deposited | Net balance | Net gain | Fee erosion |
|---|---|---|---|---|
| €100 | €30,000 | €67,825 | €37,825 | €1,474 |
| €250 | €75,000 | €169,563 | €94,563 | €3,685 |
| €500 | €150,000 | €339,127 | €189,127 | €7,370 |
| €1,000 | €300,000 | €678,254 | €378,254 | €14,740 |
With no starting sum the result scales in a straight line with the monthly amount: every €100 a month becomes €67,825 after costs in 25 years. So €1,000 a month gives ten times what €100 a month gives, and fee erosion is ten times larger in euros (€14,740 against €1,474) while the percentage stays the same.
What the horizon does at €250 a month
| Horizon | Total deposited | Net balance | Growth as share of balance |
|---|---|---|---|
| 10 years | €30,000 | €40,660 | 26.22% |
| 20 years | €60,000 | €113,613 | 47.19% |
| 30 years | €90,000 | €244,508 | 63.19% |
| 40 years | €120,000 | €479,362 | 74.97% |
Double the horizon from 20 to 40 years and the deposits double from €60,000 to €120,000, but the balance after costs goes from €113,613 to €479,362, more than 4 times as much. The difference comes from compound return on an ever larger balance.
Investing involves risk of loss. The figures presented by this calculator are for illustrative purposes only and do not constitute financial advice. Past performance does not guarantee future results.
Questions about these examples
Why is the final balance larger than what I deposited?
Each month the return is added to a balance that already holds earlier returns, so the share of growth rises with the horizon: at €250 a month, 63.19% of the €244,508 after 30 years is growth.
What if I deposited half as much?
At €125 a month for 30 years the balance after costs would be €122,254, half of €244,508, apart from rounding.
Are taxes included?
No. Tax, such as Dutch Box 3, depends on your situation and is not part of the calculation. Neither are transaction costs or dividend withholding tax.
Terms on this page
Source of the figures: the ETF calculator's own calculation engine, under the assumptions in the text. How the calculator works