THE NUMORIX GUIDE
How to use the Currency calculator
Last reviewed September 14, 2026
What this calculator does
Each supported currency has a reference value expressed as U.
Formula and method
Each supported currency has a reference value expressed as U.S. dollars per currency unit. The conversion is amount x referenceRates[from] / referenceRates[to]. When the custom option is enabled, the entered rate is used directly as units of the destination currency per one source unit.
Variables and inputs
Enter a nonnegative amount, choose a source and destination from USD, EUR, GBP, JPY, CAD, AUD, CHF, CNY, INR, and MXN, and optionally enter a custom source-to-destination rate. The amount follows the source currency and the result follows the destination currency; the reference table is a fixed code snapshot in the engine.
Worked example
Using the engine's reference values, $100 USD to EUR is 100 x 1.00 / 1.08 = 92.5926 EUR, displayed to currency precision as about EUR 92.59. If a provider quotes 1 USD = 0.91 EUR and that custom rate is selected, the same amount is 100 x 0.91 = EUR 91.00.
How to interpret the result
The result is a rate-based equivalent, not the amount a bank, card network, or exchange desk will deliver. The comparison table helps show the relative direction of the selected reference rates. Fees and bid-ask spreads reduce the amount received in a real transaction.
Common mistakes to avoid
Check the From and To selectors before interpreting the number. A rate of 1.08 EUR per USD is not the same as 1.08 USD per EUR. Do not mix a custom rate quoted in the reverse direction with the direct-rate field.
Assumptions and limitations
The reference rates are hardcoded in the engine and are not a live quote. The calculator does not model provider spreads, transfer fees, cash rates, card settlement timing, or local currency controls. JPY display rounding can hide fractions that still matter in a later calculation.