ETF calculator for lump-sum and savings-plan, with TER-honest math

An ETF calculator answers two questions at once: how much your money grows over the years, and what is left after costs and tax. Pick a lump-sum or a savings plan, enter the amount, duration and expected return, and the final value appears at once, split into contributions, growth, cost and tax.

How do I calculate the final value of an ETF savings plan?

The final value of a savings plan comes from your monthly contributions plus the compounding on top. The tool grows each contribution monthly at the expected rate divided by twelve, then sums across the term. An optional starting capital grows alongside it.

For example, 100 per month over 20 years adds up to 24,000 in pure contributions, and at 7 percent return the rest arrives as growth on top. If you also enter a starting capital, it counts too. The stacked bar chart breaks it down year by year:

• Contributions are the money you transfer yourself.
• Growth is what the market earns on top.
• Cost is the total the TER removes over time.
• Tax only appears when you switch the tax mode on.

Move a slider and the chart recomputes live. You see right away how much a higher contribution or a longer horizon lifts the end figure.

What is the difference between a lump-sum and a savings plan?

With a lump-sum you invest one amount once and let it grow. With a savings plan you pay in a fixed amount every month, optionally plus a starting capital. Both modes share one URL, and you switch at the top with a single click.

The real difference is timing. A lump-sum is fully invested from day one, so all the money works straight away. A savings plan eases in gradually and smooths the entry point, the cost-averaging effect. Historically the lump-sum tended to win over long horizons, simply because the money is invested earlier. Without a large amount to invest at once, the savings plan still builds wealth on a predictable schedule. You can save and share a link to your setup, no account needed.

How does the TER affect long-term returns?

The TER (Total Expense Ratio) is the fund's annual fee, charged on your entire balance, not just on new contributions. That is exactly why it costs more over long horizons than the small percentage suggests.

You see this honestly here: your current TER runs against a 0.75 percent reference, and the gap appears as a Euro figure, not as basis points. Cheap world ETFs often sit around 0.20 percent, while pricier products charge three to four times that. Across 20 or 30 years the difference adds up to a noticeable four-digit amount that is simply missing at the end.

Short version: 0.55 percentage points sound like nothing, but over decades they are not.

What is the Vorabpauschale, and how is it computed?

The Vorabpauschale is an annual advance tax in Germany that mainly affects accumulating funds. It stops the tax office from going empty-handed until you sell, since accumulating funds reinvest income instead of paying it out. Distributing funds can trigger it too, if their distribution falls below the base yield. Turn the tax mode on and you get a year-by-year estimate. The estimate models the accumulating, zero-distribution case; the accumulating-or-distributing choice above does not change the projection.

Here is the sequence the tool runs:

1. Base yield: Basiszins times 70 percent of the fund value at the start of the year. The German finance ministry (BMF) sets the Basiszins annually, and the tool keeps it as an input field you should check against the current value.
2. Cap: the Vorabpauschale is limited to the actual gain that year. In a loss year it is zero.
3. Partial exemption (Teilfreistellung): part stays tax-free by fund type. Equity funds (equity share from 51 percent) get 30 percent, mixed funds 15 percent, real-estate funds 60 percent.
4. Tax rate: the taxable remainder carries 25 percent Abgeltungsteuer plus 5.5 percent solidarity surcharge, about 26.4 percent combined.

The model is deliberately simplified: church tax and the saver's allowance are left out. It is not tax advice, but it surfaces what most calculators skip entirely.

What assumptions are built into this calculator?

Every projection is only as good as its assumptions, and this one states them plainly. The main one: it uses a constant annual return. Real markets fluctuate, so an average return approximates the end result without modelling any single path.

What is intentionally not included:

• No inflation. The figures are nominal, not in today's purchasing power.
• No sequence-of-returns risk. Whether good years come early or late matters a lot in the payout phase, but not here.
• Simplified tax. No church tax, no saver's allowance.

Enter a return above 15 percent or a TER above 2 percent and you get a warning, because such values are rare for serious index ETFs. You may model a negative scenario; the chart then shows the loss path. The 7 percent default return reflects the long-term average of broad world indices, but it is no guarantee for the future.

Frequently Asked Questions

Who is the savings-plan mode for?

For anyone investing a fixed amount regularly instead of a large sum at once. Enter your monthly contribution, optionally a starting capital, and see the projected final value with costs and tax. It covers exactly the intent behind searches like "etf savings plan calculator".

Why does the calculator show the TER in Euros instead of percent?

Because almost nobody thinks in basis points. 0.20 versus 0.75 percent sounds negligible, but the Euro amount across decades is not. Converting it makes the cost tangible without you having to do the arithmetic.

Is the tax estimate binding?

No. It is a simplified projection under German investment-tax rules, without church tax or the saver's allowance. For concrete decisions, consult a tax adviser or an independent fee-based adviser.