usefulweb.site Multi-Currency Invoice Calculator

Money-saving & comparison

Multi-Currency Invoice Calculator

Convert invoice lines in different currencies at ECB reference rates, with VAT, rounding and totals.

E.g. the invoice or supply date. Empty: latest ECB rates. Weekends/holidays use the last publication before.

One per line, as units per 1 EUR (ECB convention). Used with "Enter rates manually".

Invoice lines (required)
Invoice lines
#DescriptionQuantityUnit priceCurrencyVAT %
1
2
3
4
5

Try an example: EUR invoice with USD and GBP costs (manual ECB-style rates) · CHF invoice, document rounding (cross rates via EUR)

How it works

Enter invoice lines in different currencies, the invoice currency and a rate date. The calculator converts every line at the ECB euro reference rates of that date (or your own rates), applies VAT per line, shows the VAT summary and totals with either per-line or per-document rounding (and the difference between both), and writes the “converted at the ECB reference rate of …” statement. Download as CSV or an HTML table.

  • Each line’s net amount = quantity × unit price, rounded to the minor units of its own currency, then converted with the cross rate rate(invoice currency) ÷ rate(line currency), both quoted per euro by the ECB.
  • Per-line rounding: each converted net amount and its VAT are rounded to the invoice currency’s minor units and then added up. Per-document rounding: exact converted amounts are added up per VAT rate, the net subtotal is rounded and VAT is calculated once per rate. Both totals are shown, because tax authorities and accounting systems differ in which they expect.
  • Rounding is half away from zero (commercial rounding). Lines without a currency use the invoice currency; lines without a VAT rate have 0 %.
  • ECB rates for a date are the last publication on or before it (none on weekends and TARGET holidays). Manual rates are entered per euro, exactly like the ECB quotes.

Not tax advice. Check which exchange rate and rounding your tax authority requires for invoices and VAT returns.

Sources

For scripts and AI agents

  • JSON API: POST https://multicurrencyinvoicecalculator.usefulweb.site/api/v1/calculate (same calculation as this page)
  • Interface description: OpenAPI 3.1 · AI guide: llms.txt
  • MCP server (Streamable HTTP): https://multicurrencyinvoicecalculator.usefulweb.site/mcp · tool name multi_currency_invoice_calculator
Example request
curl -s -X POST https://multicurrencyinvoicecalculator.usefulweb.site/api/v1/calculate \
  -H 'content-type: application/json' \
  -d '{"invoiceCurrency":"EUR","rateSource":"manual","rateDate":"2026-10-16","manualRates":"USD 1.1253\nGBP 0.84385","lines":[{"description":"Consulting (days)","quantity":3,"unitPrice":850,"currency":"EUR","vatRate":19},{"description":"Cloud hosting","quantity":1,"unitPrice":412.37,"currency":"USD","vatRate":19},{"description":"Conference ticket","quantity":2,"unitPrice":299.99,"currency":"GBP","vatRate":7},{"description":"Travel expenses (no VAT)","quantity":1,"unitPrice":123.45,"currency":"USD","vatRate":0}],"rounding":"line"}'

Related tools

  • Currency Converter – Convert an amount into several currencies at ECB euro reference rates, with rate date and source.
  • Travel Exchange Fee Calculator – Compare what cards, ATMs, DCC and exchange bureaus really cost abroad vs the ECB reference rate.
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