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About this calculator

Disclaimer

This calculator is for informational purposes only and does not constitute tax advice. The calculations are based on the Actual Return on Investment in Box 3 Act as approved by the House of Representatives (Tweede Kamer). The bill is currently under review by the Senate (Eerste Kamer). Final rates and rules may still change. Always consult a tax advisor for your personal situation.

Privacy

All calculations are performed entirely in your browser — your financial data never leaves your device. We use privacy-friendly analytics (Google Analytics 4) to understand how visitors use the site, configured to minimize data collection with a 2-month retention period. See our Privacy & Cookies page for full details.

Sources

The information on this website is based on:

01Rijksoverheid.nl — Plans for actual return Box 3
02Actual Return on Investment in Box 3 Act (bill 36748)
03Meijburg & Co — Bill analysis
04Belastingdienst.nl — Box 3 information

Useful links

Changelog

What's new?

v4.2.0

2026-05-19

·New editorial report at /political/36748/hearing-19-mei — longread with drop cap, dek, reading-time stamp, per-speaker blocks with pull-quote format, fault-line analysis and source list
·New scenarios page at /political/36748/scenarios — four scenarios (pass, novelle, delay, withdraw) with probability estimates, triggers, timing and impact + 'what to watch' milestone timeline
·Report article marked as featured event on the homepage — the masthead and the lead news card now link directly to the longread

v4.1.1

2026-05-19

·Preview card replaced with a recap card: 'What the experts said' — positions per speaker, consensus assessment, and procedural follow-up (second written round May 26)
·Nine experts named with their positions: Jacobs and Van den Dool defending; Heithuis withdraw; Essers 'tragedy of missed opportunities'; NOB implementation complexity; VNO-NCW prefers capital-gains tax; Vastgoed Belang litigation; Van Lanschot Kempen liquidity risk; Dutch Startup Association 40% leave-propensity
·Two official Eerste Kamer committee-meeting pages (block 1 + block 2 of May 19) added as sources

v4.1.0

2026-05-18

·Live dossier masthead added beneath the hero on the homepage: latest headline, date stamp, and version. FT-style 'live blog' strip, auto-populated from the central news registry
·Homepage 'Latest updates' section is now auto-driven from lib/news-events. No more hand-edits per release; newest 3 events fill the lead + 2 secondary cards
·Relative date labels on cards: Today · Tomorrow · Yesterday · X days/weeks/months ago — computed automatically per event

v4.0.5

2026-05-18

·New preview card on the 36748 page: 'What's at stake this week'. Both blocks of the May 19 expert hearing (17:00 and 19:30) with announced speaker organisations and themes per block
·Timeline extended with the second written round (inbreng tweede verslag) on May 26, 2026 — one week after the expert hearing; only then can plenary debate begin
·Three new Eerste Kamer sources added: announcement of expert hearings (May 13), agenda for May 19, and incoming-letters index for dossier 36748

v4.0.4

2026-05-08

·Corrected chain partner lead time from 18 months to 'one year and nine months' (~21 months), per rijksoverheid.nl and kst-36748. Added sources: Explanatory Memorandum, Government response to Senate report, and rijksoverheid box 3 reform main page

v4.0.3

2026-05-08

·Added Senate Finance Committee procedural meeting (May 12): committee discusses next steps for bill 36748 now that the NnavV has been received
·Added Senate expert hearing (May 19): two 90-minute blocks with external experts — first independent expert input to the Senate since March 17

v4.0.0

2026-05-05

·Full editorial redesign (FT/Economist feel): paper/ink palette, hairline rules, kicker eyebrows, magazine layout for landing
·New typography: Source Serif 4 for headlines, Inter for body, tabular figures for all numerics
·Recharts FT-style: ink-on-paper palette, dotted gridlines, serif axis labels, no shadows
·Calculator reworked as long-form: sticky parameters panel left, 'The Verdict' with numbered figures right

v3.0.2

2026-04-28

·Timeline updated: Eerste Kamer Finance Committee submitted its report (verslag) on April 7 — one week past the deadline; institutional input from Baker Tilly and VCP highlighted
·Added Nota naar aanleiding van verslag (April 24): government answers on loss offset, real estate, start-ups, international coordination, and administrative impact

v3.0.1

2026-04-03

·Added official Eerste Kamer transcript of oral consultation with State Secretary Eerenberg: novelle planned for Prinsjesdag, three-pillar response, life events research, June letter promised, timeline updated

v3.0

2026-03-30

·Added Box 3 demographic data from March 17 briefing: 2.6M taxpayers, €651B total wealth breakdown, revenue concentration statistics
·New 'What changes for you' section: VIA pre-fill drop (85% → 64%), 7-year record-keeping obligation, toeslagen volatility risk, Step-Up mechanism
·Added explanation of the 'fiscal sieve' (keuzeregime) — why the current system is legally untenable
·New implementation section: CoolGen five red flags, 900 FTE staffing need, chain partner deadlines
·Added J-Curve revenue projection pattern from Ministry micro-simulations (projecting to 2060)
·New FAQ section: Step-Up reset, record-keeping rules, deposit/withdrawal filtering, toeslagen impact
·New FAQ section: Why the Netherlands chose the hybrid model, international comparison

v2.9

2026-03-30

·Real estate deemed return corrected from 3.55% to 3.35% of WOZ value (confirmed by March 17 briefing: 10th percentile of market rental values)
·Added implementation details from March 17 briefing: 18-month chain partner lead time, CoolGen sunset deadline, 1-year carry-back discussion (est. €1B cost)

v2.8

2026-03-18

·Box 3 vote results corrected based on eerstekamer.nl: DENK moved to against, Groep Markuszower added, party counts updated
·Senate status updated: March 17 technical briefing and oral consultation completed, expert symposium after May recess, March 31 report deadline

v2.7

2026-03-15

·New Updates page: political developments timeline and site changelog in one place
·Updated Box 3 timeline: coalition agreement, social media protests, government adjustment letter, and missed Senate deadlines

v2.6

2026-02-26

·Full legislative archive: 25+ bill detail pages with timeline, status, and vote history

v2.5

2026-02-25

·Senate status updated: Finance Committee has begun review of bill 36748, timeline and deadlines updated

v2.4

2026-02-23

·Added Norway and Sweden to international tax comparison

v2.3

2026-02-22

·Mortgage and toeslagen data now persists when switching between pages

v2.2

2026-02-22

·Interactive projection charts for portfolio growth and cumulative tax burden

v2.1

2026-02-20

·Added site logo and favicon

v2.0

2026-02-20

·6 return models: Linear, S&P 500 (2010–2024), S&P 500 (2000–2014), AEX (2010–2024), Bear market, and Monte Carlo
·Winst scenario now shows deferred tax and net if sold — fairer comparison with aanwas
·Expanded table with grouped columns for all three scenarios
·International comparison now uses the selected return model
·Monte Carlo simulation with re-roll button for randomized market scenarios

v1.2

2026-02-18

·Distinguish between actual and taxable returns per scenario

v1.1

2026-02-17

·Historical S&P 500 simulation (2010–2024) added
·Improved mobile layout

v1.0

2026-02-16

·Initial release with projection, international comparison, and three tax scenarios