# Realtime exchange rates: 165+ fiat and 130+ crypto > Convert Currencies Online, updated to today's rates. Convert USD to EUR or BTC to USD. 297 assets across 165+ fiat (EUR, USD, GBP) and 130+ crypto (BTC, ETH). Free in-browser tool (no upload): https://www.mauriziofonte.it/tools/currency-converter Conversion across **297 assets**: **165+ ISO 4217 fiat currencies** (EUR, USD, GBP, JPY, CHF, down to minor ones like YER, ZAR, ZMW) and **130+ cryptocurrencies** (BTC, ETH, USDT, SOL, ADA, AVAX, ARB). **Fiat / Crypto / All tabs** to filter the dropdown, or a unified dropdown with separate optgroups for fiat/crypto cross-conversion. **Historical chart** over 30/90/180 days with min, max, average and percent change. ## How to use the converter 1. **Pick the tab** - **Fiat** (default): legal currencies only (EUR, USD, GBP, JPY...). **Crypto**: only cryptocurrencies and tokens (BTC, ETH, USDT, SOL, ADA...). **All**: unified dropdown with separate optgroups for fiat and crypto, useful for cross-conversion (e.g. EUR -> BTC, USDT -> JPY). 2. **Enter amount and assets** - Amount accepts numbers with comma or period (US: `1,234.56` or `1234.56`). The two 'From' and 'To' dropdowns are sorted by asset name. Quick search: type the first letter in the select and the browser autocompletes (e.g. 'B' opens Bitcoin, Bahamian Dollar, etc). 3. **Press 'Convert'** - Output: converted amount, applied rate and rate date. For crypto with low value (e.g. SHIB, PEPE), the tool automatically increases decimal precision up to 8 digits to avoid rounding that would mask the result. 4. **Display the history** - Below the result the exchange rate history chart appears. Tabs 30/90/180 days to switch between the three periods. Auto-scaled X (dates) and Y (rate) axes, with inline summary of minimum, maximum, average and percent change for the period. Works identically for fiat-fiat, crypto-crypto and fiat-crypto pairs. ## Dataset, coverage and history **297 assets, full coverage.** The tool exposes **165+ fiat currencies** (all active ISO 4217, plus some recently retired transition codes: HRK Croatian pre-EUR, SLL Sierra Leone pre-redenomination and similar) and **130+ cryptocurrencies** aggregated daily from public sources (ECB for fiat, exchange aggregators for crypto). No arbitrary subsets: the Fiat / Crypto / All filter reduces visual noise in the dropdowns, it does not limit coverage. **Mid-market rates, no retail spread.** The rates shown are mid-market (average between bid and ask). Banks and currency exchanges typically apply a 2-5% retail spread on top of this value, and higher on exotic currencies or low-volume crypto. For planning, preliminary accounting and cross-border reporting the mid-market rate is the correct baseline; for the rate actually applied to a market transaction, add the spread of the specific intermediary. **30, 90 or 180-day queryable history.** The chart samples 30 evenly distributed points across the selected period (daily for 30 days, every 3 days for 90, every 6 for 180) and reports min, max, average and percent change for the period. The Y-axis scale auto-adapts to the order of magnitude, working seamlessly with typical fiat rates (1.08 EUR/USD) and crypto fractional rates (0.000017 SHIB/USD). For long-term analysis beyond 180 days: ECB Stats Data Warehouse for fiat (history back to 1999), exchange-specific historical APIs for crypto. ## Glossary - **ISO 4217**: International standard for 3-letter currency codes (EUR, USD, GBP...). Maintains a list of active currencies (~165), retired ones, and supranational codes (XAU gold, XAG silver, XDR Special Drawing Rights). The tool uses this list to automatically classify fiat vs crypto. - **Mid-market rate**: Average rate between bid (price the market buys the currency at) and ask (price it sells at). It's the 'theoretical' rate without spread. Banks and currency exchanges apply 2-5% retail spreads (sometimes higher on exotic currencies or crypto). - **Market cap (crypto)**: Cryptocurrency market capitalization = unit price x circulating supply. Top market cap 2026: BTC, ETH, USDT, USDC, BNB, SOL, XRP, ADA, AVAX, DOGE. Some tokens in the dataset have very low cap (low-cap altcoins): watch for volatility. - **Stablecoin**: Crypto pegged to a fiat currency (usually USD) or asset (gold). Examples: USDT, USDC, DAI, BUSD. The rate stays close to 1 USD but fluctuates slightly (historic de-pegging events noted in 2022 with UST -> $0). - **Rate aggregator**: Service that collects rates published by primary sources (ECB for European fiat currencies, national central banks, exchange aggregators for crypto) and exposes them in a uniform format. Aggregation cadence is daily, in line with the publication schedule of the institutional sources. For intraday trading analysis the correct sources are direct exchange APIs. - **Cross-rate**: X -> Y conversion where neither X nor Y is the provider's reference currency. Computed via cross: X -> reference -> Y. Example: BTC -> JPY = (BTC -> USD) x (USD -> JPY). The tool computes this and shows the final result directly. ## Frequently asked questions ### How many assets are supported exactly? 297 assets at the moment: 165+ fiat and 130+ crypto. The exact count fluctuates slightly when the aggregator adds or removes assets, which is rare. Classification between Fiat and Crypto is automatic: 3-letter ISO 4217 codes (EUR, USD, JPY) end up in the Fiat tab, the rest in the Crypto tab. ### Are crypto rates real-time? No, they are **updated once per day**. For intraday crypto analysis (minute-to-minute volatility) the right sources are direct exchange APIs from Binance, Coinbase or Kraken, or commercial aggregators. For planning, preliminary accounting and cross-border reporting, the daily rate is adequate. ### Are fiat rates ECB end-of-day? They are **derived from aggregate sources**, ECB being one. They are not published as official ECB rates (they don't come directly from the institutional site). For audits requiring strict ECB rates (tax filings, cross-border contracts, expert reports) the canonical source is the ECB Stats Data Warehouse (`sdw.ecb.europa.eu`); this tool should be treated as a preliminary estimate. ### Can I convert fiat to crypto directly? Yes. **All** tab: the unified dropdown shows Fiat and Crypto in separate optgroups. Pick EUR (Fiat) as 'From' and BTC (Crypto) as 'To', click Convert. Also works in reverse (BTC -> EUR) and between crypto-crypto pairs (BTC -> ETH). ### Are low-cap cryptocurrencies reliable? It depends. For the top 50 (BTC, ETH, USDT, USDC, BNB, SOL, XRP, ADA, AVAX, DOGE) rates are solid: high trading volume, ample liquidity, tight bid-ask spread. For low-cap assets (minor DeFi tokens, NFT-related tokens), the daily mid-market rate may be poorly representative on low-volume days. For investment decisions, always verify across two or three independent sources. ### What are XAU, XAG, XDR in the Fiat tab? Supranational ISO 4217 codes. **XAU** = troy ounce of gold. **XAG** = troy ounce of silver. **XDR** = IMF Special Drawing Rights, a basket of reserve currencies. Technically not fiat but monetary reserve assets; they are classified as ISO 4217 and therefore grouped in the Fiat tab by convention. ### How far back does the history go? The tool exposes 30, 90 or 180 days of history. For multi-year analysis, the reference source for fiat is the ECB Stats Data Warehouse (history back to 1999); for crypto, history depends on the asset and should be queried on individual exchange or aggregator APIs. --- Tool by Maurizio Fonte, senior backend engineer. All tools: https://www.mauriziofonte.it/tools/