The detailed guide below is currently available in English.
Where the fees hide
Exchanges usually quote a maker/taker fee as a percentage of each trade’s value, and both legs of a round trip cost you: one fee when buying, another when selling. On a leveraged or high-frequency strategy those percentages compound into a serious drag, and spreads, withdrawal fees, and conversion charges can add more. Model your actual fee tier rather than the headline 0% marketing number.
A volatile market needs a wider lens
Crypto can deliver double-digit moves in a day, so a single buy-sell snapshot says little about a strategy. Consider what a 30% drawdown after your buy would do to the plan, whether you would hold or exit, and how taxes apply — in the US, each sale or swap is a taxable event just like a stock. Position sizing you can live with beats any projected return.
Contexto local: Portugal
Dados locais essenciais para cálculos financeiros em Portugal — diferem dos valores padrão dos EUA:
- IVA: Taxa normal 23 % (continente), intermédia 13 %, reduzida 6 %. Os preços ao consumidor já a incluem.
- IRS (2025): Taxas progressivas de 13,25 % a 48 %, mais taxa solidária e majoração ACR (Açores e Madeira têm deduções próprias).
- Segurança Social: Taxa contributiva global 34,75 % — 11 % a cargo do trabalhador sobre o bruto, 23,75 % da entidade patronal.
- Salário mínimo 2025: 870 € por mês, pagos em 14 prestações (12 + subsídios de férias e de Natal).
- Gorjeta: Não é obrigatória; 5–10 % em restaurantes é bem-visto.
Atualizado: outubro 2026 · valores de 2025, fontes oficiais acima.
Perguntas frequentes
How are the fees calculated?
Each fee applies to that leg’s dollar value: the buy fee to the amount you paid, the sell fee to the amount you received. Enter 0 if your exchange charges no trading fees.
Can I enter fractions of a coin?
Yes — crypto trades in fractions, so 0.5, 0.021, or any decimal quantity works. The math scales the fees proportionally.
Do I owe tax on crypto gains?
In the US and most countries, yes: selling or spending crypto at a gain is a taxable event. Short-term gains usually follow income tax rates and long-term gains the capital gains schedule.