A currency pair quotes how much of one money buys one unit of another. Every rate therefore has a direction, and reading it backwards is the most common mistake: if one euro buys 1.08 dollars, then one dollar buys about 0.926 euros, not 1.08.
Rates that appear in search results and on this page are mid-market rates — the midpoint between the prices at which banks are willing to buy and sell large quantities of a currency from each other. That market is the wholesale one, where the minimum trade runs to millions. It is the correct reference for comparing currencies and the wrong assumption for what you will be offered at a counter or on a card.
The tool holds every rate against a single base, the US dollar, and converts by dividing the two:
rate = rate_of_target ÷ rate_of_source
result = amount × rate
Because both legs are stored per dollar, the dollar cancels out of the division exactly. A euro-to-yen conversion is therefore just as accurate as a dollar-to-yen one — no triangulation error is introduced, even though the arithmetic passes through a currency you never mentioned. The page displays the resulting rate to four decimal places and the converted amount in the target currency's own format, and it lists the amount re-expressed in the first twelve currencies as a quick reference line.
Twenty-eight currencies are listed, spanning the major pairs, the Asian and Pacific currencies, and several emerging-market ones. Rates are fetched once when the page loads and cached; the figures held in the code serve as a fallback if that request fails, which is why an offline visit still returns a number.
Dollars to yuan. Converting 100 USD to CNY with the fallback rate of 7.12 yuan per dollar: the rate is 7.12 ÷ 1 = 7.1200, and 100 × 7.12 = 712.00 CNY.
A cross rate that never touches your own currency. Converting 100 EUR to JPY uses 0.92 euros per dollar and 149.5 yen per dollar. The rate is 149.5 ÷ 0.92 = 162.5000, so 100 euros buys 16,250 JPY. Reading the intermediate dollar figures makes it look as though dollars were involved; they are not, and the answer is the same as if the yen had been stored in euros directly.
Working in the other direction is a division, not a multiplication: finding what 712 CNY is worth in dollars means dividing by 7.12 to recover 100.
Because a retail conversion includes the spread and often a fee on top. The mid-market rate is the wholesale midpoint between banks; nobody sells currency to consumers at it.
Almost always the local currency. Choosing your home currency at a terminal or cash machine uses the merchant's own conversion rate, which is typically several per cent worse than the card network's.
Whichever convention your jurisdiction prescribes — commonly the rate on the transaction date or a monthly average — taken from a designated source. A live converter is a cross-check, not a valuation authority.
Because the rates are refreshed on load from a live feed. Small differences between visits are the market moving, not a calculation error.
Yes, and it will return the original figure exactly, since one conversion multiplies by the rate and the reverse divides by it. The round trip is lossless here; with real dealer spreads it would not be.