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Free calculators for index investing and financial independence

Thirteen interactive tools — no sign-up, no ads, work offline. Understand compound growth and fees, decide your allocation, run the numbers on DCA vs. lump sum, and find out when you can live off your portfolio.

These tools are the free, country-agnostic companion to Fondos indexados, a Spanish-language book on index investing in Spain. The book itself — and 10 more tools covering Spanish tax rules — is only available in Spanish for now.

Thirteen tools, four steps

The same order a new investor actually needs them in: understand the terrain, decide your portfolio, execute the plan, and figure out when you can live off it.

Understand

What time and fees actually do to your money.

Decide

Design your portfolio's stock/bond split.

Execute

Put the plan in motion and keep it on track.

Independence

When you can stop, and how much you can withdraw.

Why only 12 of the 21 tools are here

The other 9 — capital gains tax, tax-loss carryforwards, pension plans, a Spanish fund comparator — only make sense for someone filing taxes in Spain. Rebuilding them for a US/UK audience would mean inventing numbers instead of translating real ones, so they stay Spanish-only rather than becoming a worse, generic version of themselves.

See the full Spanish site →