Exchange Rates
Look up the Central Bank's official PTAX rate and convert values between Real and foreign currency.
The currency you choose is sent to the Nexinon server, which queries the public PTAX API from Brazil's Central Bank on your behalf and caches the result (public data — the day's rate, unrelated to who looked it up) for up to 15 minutes, for faster responses on later lookups. No lookup is logged tied to you.
Currency
The API behind this tool
This tool queries the PTAX API from Brazil's Central Bank, a free public API with no access key required — the Nexinon server does the lookup on your behalf and caches the result (public data) for up to 15 minutes.
GET .../PTAX/.../CotacaoMoedaPeriodo(moeda,dataInicial,dataFinalCotacao)
{
"cotacaoCompra": 5.2037,
"cotacaoVenda": 5.2043,
"dataHoraCotacao": "2026-08-18 13:10:39.550019",
"tipoBoletim": "Fechamento"
}What PTAX is
PTAX is the official exchange rate calculated by Brazil's Central Bank from the average of interbank foreign-exchange market trades throughout the day, consolidated in the closing bulletin. It's the rate used as the official reference in contracts, financial statements, income tax filings, and other obligations — quite different from the market rate shown at exchange bureaus and brokers, which bakes in a spread and varies by provider.
Why PTAX differs from the rate you see at an exchange bureau
The commercial or tourism rate charged to the public includes each institution's profit margin (spread), so it's always less favorable than PTAX — buying dollars costs more than the PTAX sell rate, and selling dollars pays less than the PTAX buy rate. PTAX isn't a rate you can trade directly on; it's the official reference used in contracts and tax obligations, not a counter price.
Why not every day has a rate
The Central Bank only publishes a PTAX bulletin on foreign-exchange trading days — there's no rate on weekends or national holidays. That's why the rate shown is always from the most recent trading day with a published bulletin, which can be one or more days before today's date.
Frequently asked questions
No. It's the official PTAX close from the most recent trading day with a published bulletin — the value used in contracts and tax obligations, which changes at most once per trading day, never in real time within the day itself.
Same logic as any currency trade: "buy" is the rate at which the market buys the foreign currency, "sell" is the rate at which it sells it — the gap between the two is the interbank market's own spread. This tool's converter always uses the sell rate, the one most commonly cited as "today's rate".
The history shows daily closes — weekends and national holidays have no PTAX bulletin (see "Why not every day has a rate", above), so those days simply don't appear in the series.
From the public PTAX API of Brazil's Central Bank (bcb.gov.br), free and requiring no access key — see "The API behind this tool", above.
Those are exactly the currencies that make up the Central Bank's official PTAX bulletin — US Dollar, Euro, British Pound, Japanese Yen, Swiss Franc, Canadian Dollar, Australian Dollar, and the three Scandinavian kroner (Danish, Norwegian, and Swedish). Other currencies don't have a published PTAX rate.
No. Only the rate itself (public data) is cached on our server — which currency you looked up is never logged tied to you.
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