diff --git a/src/components/DeckCostCalculator.tsx b/src/components/DeckCostCalculator.tsx
index 44f7a82..489d920 100644
--- a/src/components/DeckCostCalculator.tsx
+++ b/src/components/DeckCostCalculator.tsx
@@ -33,6 +33,23 @@ const CURRENCY_SYMBOLS: Record<string, string> = {
   ILS: '₪', PKR: '₨', BDT: '৳', LKR: 'Rs', NPR: 'Rs',
 };
 
+/** ISO-4217 fiat codes — the only unit currencies we offer (plus `sats`). Keeps
+ *  crypto/stables (BTC, ETH, USDT, …) out of the picker. */
+const FIAT_CODES = new Set([
+  'AED', 'AFN', 'ALL', 'AMD', 'ANG', 'AOA', 'ARS', 'AUD', 'AWG', 'AZN', 'BAM', 'BBD', 'BDT', 'BGN',
+  'BHD', 'BIF', 'BMD', 'BND', 'BOB', 'BRL', 'BSD', 'BTN', 'BWP', 'BYN', 'BZD', 'CAD', 'CDF', 'CHF',
+  'CLP', 'CNY', 'COP', 'CRC', 'CUP', 'CVE', 'CZK', 'DJF', 'DKK', 'DOP', 'DZD', 'EGP', 'ERN', 'ETB',
+  'EUR', 'FJD', 'FKP', 'GBP', 'GEL', 'GGP', 'GHS', 'GIP', 'GMD', 'GNF', 'GTQ', 'GYD', 'HKD', 'HNL',
+  'HRK', 'HTG', 'HUF', 'IDR', 'ILS', 'IMP', 'INR', 'IQD', 'IRR', 'ISK', 'JEP', 'JMD', 'JOD', 'JPY',
+  'KES', 'KGS', 'KHR', 'KMF', 'KRW', 'KWD', 'KYD', 'KZT', 'LAK', 'LBP', 'LKR', 'LRD', 'LSL', 'LYD',
+  'MAD', 'MDL', 'MGA', 'MKD', 'MMK', 'MNT', 'MOP', 'MRU', 'MUR', 'MVR', 'MWK', 'MXN', 'MYR', 'MZN',
+  'NAD', 'NGN', 'NIO', 'NOK', 'NPR', 'NZD', 'OMR', 'PAB', 'PEN', 'PGK', 'PHP', 'PKR', 'PLN', 'PYG',
+  'QAR', 'RON', 'RSD', 'RUB', 'RWF', 'SAR', 'SBD', 'SCR', 'SDG', 'SEK', 'SGD', 'SHP', 'SLL', 'SOS',
+  'SRD', 'SSP', 'STN', 'SYP', 'SZL', 'THB', 'TJS', 'TMT', 'TND', 'TOP', 'TRY', 'TTD', 'TWD', 'TZS',
+  'UAH', 'UGX', 'USD', 'UYU', 'UZS', 'VES', 'VND', 'VUV', 'WST', 'XAF', 'XCD', 'XOF', 'XPF', 'YER',
+  'ZAR', 'ZMW',
+]);
+
 /** How a currency is shown: `$1.00`, `CHF 1.00`, `1,000 sats`. */
 function formatMoney(v: number, cur: string): string {
   if (cur === 'sats') return `${Math.round(v).toLocaleString()} sats`;
@@ -119,7 +136,9 @@ export function DeckCostCalculator() {
   const fmt = (n: number) => formatMoney(Number.isFinite(n) ? n : 0, cur);
 
   const currencies = useMemo(() => {
-    const fiat = rates ? Object.keys(rates).sort() : ['USD', 'EUR', 'GBP'];
+    const fiat = rates
+      ? Object.keys(rates).filter((c) => FIAT_CODES.has(c)).sort()
+      : ['USD', 'EUR', 'GBP'];
     return ['sats', ...fiat];
   }, [rates]);
   const filteredCurrencies = query