JA→jafinance.xyzCrypto · True P&L
About

An independent crypto P&L reference, reviewed by a working blockchain analyst.

jafinance.xyz publishes a single calculator with one job: report the after-fee, after-network-cost realised P&L on a crypto position, with a tax-impact preview. Reviewed by a CBP-certified blockchain analyst based in El Salvador.

Why this site exists

The P&L figure displayed by major crypto exchanges typically ignores broker fees, network fees, and spread. Across hundreds of trades over a multi-year holding cycle, the gap between displayed P&L and realised P&L can easily reach 5–15 % of the position. jafinance.xyz publishes the after-fee figure correctly and adds a tax-impact preview so traders can budget the obligation rather than discover it at filing time.

Editorial principles

  • After-fee, after-tax accuracy. Cost basis includes broker and network fees on entry. Net proceeds subtract broker and network fees on exit. Tax preview reports the four most-cited jurisdictional rates.
  • No price feeds. The calculator does not pull live coin prices. You enter the actual prices you transacted at, which is what matters for P&L reconciliation.
  • Named accountability. Valeria Méndez-Rivas, PhD CBP, is the responsible reviewer. Her CBP certification is verifiable through the CryptoCurrency Certification Consortium (C4) public directory.
  • No commercial relationships. The site does not earn referral fees from any exchange, wallet provider, tax software, or trading platform.
  • Privacy by architecture. Buy price, sell price, amounts, and fees stay in your browser.

Verification methodology

  1. Math. Cost-basis and proceeds formulas verified by inspection.
  2. Tax rates. Sourced from IRS Publication 544 (US), HMRC Capital Gains Manual (UK), and country-by-country EU summaries from each country's tax authority. Refreshed annually.
  3. Reference cases. 18 input/output pairs covering BTC, ETH, SOL, stablecoin, and loss scenarios. Every release runs against the list.
  4. Cross-check. Outputs reconciled against CoinTracker and Koinly's calculation engines on the same inputs.

The team

jafinance.xyz operates as a one-person editorial project alongside Valeria's blockchain analytics consultancy. Valeria reviews every release of the calculator and every page of reference content before publication. She holds final editorial authority and is the named accountable person for every figure on the site.

A part-time research associate based in San Salvador maintains the tax-rate refresh pipeline (downloading IRS, HMRC, and EU member-state guidance each January after rate changes are published). The associate is named in the public changelog only when their input has produced a substantive change.

What this site is not

  • Not regulated tax advice. The tax preview is illustrative. For specific filing decisions, use specialised crypto-tax software (CoinTracker, Koinly, TaxBit) or a qualified tax preparer in your jurisdiction.
  • Not a portfolio tracker. We do not pull on-chain data, scrape exchange APIs, or aggregate holdings.
  • Not a price feed. The calculator does not look up live prices. You enter actual transaction prices.
  • Not for staking, mining, or airdrop accounting. Those events have their own tax treatments and require dedicated software. The tax events page outlines the categorisation but the calculator does not handle them.

Get in touch

Calculation queries, tax-rate refresh requests, content corrections, and partnership enquiries are all handled through the contact page. We commit to acknowledging every well-formed message within 24 business hours.