The calculator
Pick a preset (MSCI World ETF, S&P 500, etc.) or freely adjust each parameter. Results update live, and the chart projects the evolution of your capital over the entire horizon.
📊 Strategy
💰 Your contributions
📈 Market assumptions
📋 Costs & Belgian taxation
📊 Your results
📈 Evolution over the horizon
💸 Costs & taxes breakdown
📉 Effect of inflation
🆚 Comparison with alternatives
How to read the results?
Belgian ETF taxation in 2026
| Tax | When? | Rate |
|---|---|---|
| TOB — stock exchange tax | On each buy and each sell | 0.12% EU acc ETF · 1.32% distributing ETF (capped at €4,000) · 0.35% stocks |
| Withholding tax on dividends | On dividends paid out (distributing ETFs + stocks) | 30% — withheld at source by the broker |
| 10% capital gains tax ⚠️ new 2026 | At resale, on the capital gain | 10% — exemption on the first €10,000 per year |
| Reynders tax | On the bond portion of mixed ETFs (> 10% bonds) | 30% on bond capital gain at resale |
| TER — ETF expense ratio | Annual, deducted directly by the issuer | 0.07 to 0.30% for passive ETFs · 1-2% for active funds |
An accumulating ETF automatically reinvests dividends without triggering the 30% withholding tax. You only pay the 0.12% TOB on buy/sell + the 10% capital gains tax on exit. It's the simplest tax optimisation for a Belgian investor.
Calculation assumptions
| Item | Method |
|---|---|
| Compounding | Monthly. Annual return converted into equivalent monthly rate. |
| DCA | Contribution at the end of each month, with TOB applied to each contribution. |
| TER | Deducted proportionally each month on the average capital. |
| Capital gains 2026 | 10% on the capital gain at resale, cumulative €10,000/year exemption. |
| Withholding on dividends | 30% on ~30% of annual return for a distributing ETF. |
| Reynders | Applied if > 10% bonds in the ETF. 30% on bond capital gain. |
| Inflation | Compounded monthly. Real value = net capital / (1 + inflation)^horizon. |
| Savings account | Monthly compounding at the rate entered (simplification — we ignore the 30% withholding tax above exempt interest). |
The tool does not cover: actual market volatility (returns are not linear — there will be years at -20%), the timing of DCA, future tax changes, synthetic vs physical ETFs, buying through a branch 23 life insurance, or optimisation via holding/company. For a real strategy, get it validated by an independent financial adviser.
3 levers that change everything
Doubling the horizon often triples the outcome. The last 10 years weigh more than the first 15 (snowball effect).
Switching from a 1.8% fee fund to a 0.15% ETF can mean 30% more final capital over 25 years. The simplest and most powerful lever.
Automatic monthly DCA statistically beats "I'm waiting for the right moment". Stopping trying to time the market frees time and boosts returns.
🧠 New to ETFs?
The complete ETF Belgium guide: choosing a broker, building a portfolio, classic mistakes to avoid.