Czech koruna (CZK) exchange rate API

The Czech Republic is tightly integrated into European manufacturing supply chains, especially the automotive sector, so most of its trade is invoiced in euros. That makes EUR/CZK the pair Czech businesses watch, and its history contains one of the clearest policy experiments in modern FX. The fxapi CZK exchange rate API gives you koruna rates against 190+ currencies, live and back to 1999 – for e-shops pricing in korunas, suppliers invoicing in euros and groups consolidating Czech subsidiaries.

CZK facts for developers

• Where it’s used: the Czech Republic.
• Symbol and formatting: Kč after the amount, a space as thousands separator and a comma as decimal separator: 1 234,50 Kč.
• Minor unit: 2 decimals (haléře). Haléř coins were withdrawn in 2008, so cash totals are rounded to whole korunas, while invoices and card payments can still show haléře.
• Central bank: the Czech National Bank (CNB).
• Regime: managed float with an inflation target. The Czech Republic joined the EU in 2004 but has not adopted the euro.
• Events in the historical data: on 7 November 2013 – the sample date on this page – the CNB started using the exchange rate as a monetary policy instrument, committing to keep the koruna weaker than about 27 CZK per euro. It ended the commitment on 6 April 2017, after which the koruna strengthened.

Get CZK rates with the fxapi API

For a day-by-day view of a policy change, /v1/range with accuracy=day (Professional plan and up) returns the series in one request. This PHP snippet downloads EUR/CZK around the April 2017 exit as CSV:

<?php
$query = http_build_query([
    'base_currency'  => 'EUR',
    'currencies'     => 'CZK',
    'datetime_start' => '2017-03-27T00:00:00Z',
    'datetime_end'   => '2017-04-21T23:59:59Z',
    'accuracy'       => 'day',
    'format'         => 'csv',
]);

$ch = curl_init("https://api.fxapi.com/v1/range?$query");
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER     => ['apikey: ' . getenv('FXAPI_KEY')],
    CURLOPT_TIMEOUT        => 15,
]);
$csv    = curl_exec($ch);
$status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

if ($status !== 200) {
    throw new RuntimeException("fxapi returned HTTP $status");
}

$rows   = array_map('str_getcsv', explode("\n", trim($csv)));
$header = array_shift($rows); // datetime,base_currency,currency,value
foreach ($rows as $r) {
    $row = array_combine($header, $r);
    printf("%s  EUR/CZK %.4f\n", substr($row['datetime'], 0, 10), $row['value']);
}

On the Free plan, /v1/historical returns single days. Related: time series API, PHP guide, and the regional peers Polish zloty and Hungarian forint.

Things to watch

• Official vs market rate. Statutory bookkeeping may require the CNB’s published rate; fxapi is ideal for pricing, analytics and management reporting.
• Cash rounding to whole korunas applies only to cash payments.
• Floor-period data looks flat. Between late 2013 and April 2017 EUR/CZK sat near 27 – don’t mistake that for stale data.

Popular CZK pairs

Request any of these pairs – or any other combination of the 190+ supported currencies – with base_currency=CZK:

Monthly averages and fluctuation for CZK

# Monthly average CZK rates for 2025 (IAS 21 / ASC 830)
curl -G "https://api.fxapi.com/v1/average" \
  -d date_from=2025-01-01 -d date_to=2025-12-31 -d period=month \
  -d base_currency=CZK -d currencies=EUR,USD,PLN \
  -H "apikey: $FXAPI_KEY"

# How did CZK move over the last year?
curl -G "https://api.fxapi.com/v1/fluctuation" \
  -d date_from=2025-10-01 -d date_to=2026-10-01 \
  -d base_currency=CZK -d currencies=EUR,USD,PLN \
  -H "apikey: $FXAPI_KEY"

See the historical exchange rates API, average rates API and documentation for every parameter.

CZK is one of 190+ currencies in fxapi, the foreign exchange rates API for developers – live rates, daily history since 1999 and monthly averages with one API key.

Frequently asked questions