How CurrenciesLive calculates its numbers
Every rate page shows a live mid-market rate, a position within the 12 month range and a volatility figure. This page explains where each number comes from, how it is calculated and what it cannot tell you.
The live rate
Rates come from the ExchangeRate-API open endpoint, which aggregates interbank quotes into a mid-market reference for more than 160 currencies. CurrenciesLive refreshes the feed every few minutes and caches it at the edge for no longer than ten minutes.
The mid-market rate is the midpoint between the buy and sell price of a currency pair. It is not a rate you can transact at. Banks and transfer providers add a margin and often a fixed fee, so the rate you are offered will be worse than the one shown here.
Daily history and chart data
Charts and range figures use European Central Bank reference rates published through frankfurter.dev. The ECB publishes one fixing per business day, around 16:00 CET, so weekends and public holidays carry the previous close.
The ECB covers 31 currencies. Pairs outside that set, such as USD to MAD or USD to AED, show the live rate and the conversion tables but no chart and no rate context block.
12 month percentile
We take every daily close in the last 365 days and count how many are at or below the current mid-market rate. That share, rounded to a whole number, is the percentile.
- 90% means the rate was at or below today's level on 90% of the trading days in the past year.
- 10% means today's rate is near the bottom of its 12 month range.
The percentile describes the past. It says nothing about where the rate goes next, and a rate can stay near a 12 month high or low for months.
30 day range
The high and low are the maximum and minimum daily closes in the last 30 days of published data, with the date of each fixing. The range percentage is the distance between the two, divided by the low.
Volatility
Volatility measures how much the rate moved, not which direction it moved. We calculate daily log returns from consecutive closes, take the sample standard deviation and annualise it with the square root of 252 trading days.
The 30 day figure uses the last 30 returns. The median is the same calculation run over every rolling 30 return window in the past year, then sorted and sampled in the middle. A current figure above the median means the pair has been moving more than usual.
The comparison line uses the average 30 day volatility of six major pairs: EUR/USD, USD/JPY, GBP/USD, USD/CHF, AUD/USD and USD/CAD.
Limits and corrections
Reference rates are daily snapshots. Intraday moves, weekend gaps, provider margins and fees are not included. Nothing on this site is investment, tax or financial advice, and past volatility does not predict future rates.
If you find a calculation error, email [email protected] with the pair and the date.
Last updated . Rate context refreshes with the underlying feeds.