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Planning tool

Portfolio Forecast Calculator

Model how contributions, return assumptions, inflation, dividends, and country tax defaults affect a long-term portfolio path.

Run a scenario

Start with a simple contribution plan. Open advanced settings only when you need more control.

Current invested amount in EUR.
Recurring amount added every month.
Time horizon
Nominal return assumption before optional inflation adjustment.
This model compounds monthly and applies dividend tax defaults from the selected country profile. Capital gains realization timing is not modeled here.
Projected value
€134,248
Total contributions
€85,000
Estimated growth
€49,248
Projected value€134,248
Total contributions€85,000
Estimated growth€49,248

Projected portfolio path

5% net annual growth assumption after optional inflation adjustment.
Projected portfolio value over 10 years for the selected country, ending at €134,248.

Tax drag comparison

Estimated annual total tax (wealth-tax drag + dividend tax) in rolling 12-month buckets (Y1..Yn).

Tax impact details (Primary)

Wealth tax drag (effective)0%
Annual wealth tax (est.)€0
Dividend tax15%
Realized gain tax0%
Unrealized gain tax0%
Dividend yield after tax1.7%
Yearly dividend tax drag0.3%
Using Netherlands Box 3 (2026) with fictional return and tax rate assumptions.

Tax model confidence

Primary
Accuracy75%
Last reviewFeb 25, 2026
Estimated uncertainty (annual drag)+/-0.034%
Estimated uncertainty (drag @10Y)+/-0.107%
Estimated uncertainty (wealth tax/yr)+/-€0
Moderate model confidence: core portfolio tax treatment is modeled for this country. Some country-specific edge cases are still simplified. No per-country source reference is attached yet.

How this helps you plan

Use this portfolio forecast calculator to test contribution plans, compare tax-country assumptions, and set realistic long-term expectations before you invest more.

Best for

  • Estimating future portfolio value from monthly investing
  • Comparing countries with different dividend and wealth-tax drag
  • Seeing how inflation and dividend reinvestment change outcomes

Important limitations

  • Market volatility and sequence-of-returns risk are simplified
  • Broker fees, FX costs, and account-level tax exceptions are not fully modeled
  • Results are scenario estimates, not personalized tax or investment advice

Frequently asked questions

Clear answers on assumptions, tax modeling, and how to use the forecast responsibly.

Build your portfolio with a long-term view

Start tracking today, automate over time, and stay consistent as your investments grow.

Founder pricing offers early access to a tool you can keep using for years.

Founder pricing applies to all plans while spots remain available.

Basic

For investors starting with a simple, manual portfolio setup

EUR 6,99/month
14 day trial
1 year historical backfill
CSV import
Daily price updates
Start Basic

Advanced

For investors ready to automate their portfolio with broker connections

EUR 9,99/month
14 day trial
10 year historical backfill
Broker integration
Daily price updates
Start Advanced

Pro

For investors who want full history and real-time market visibility

EUR 14,99/month
14 day trial
30 year historical backfill
Broker integration
US live pricing
Start Pro
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