About the AUD/SAR rate
The AUD/SAR rate is how many SAR one Australian dollar buys. It moves constantly with interest-rate expectations, commodity prices and global risk sentiment - see what moves the rate. Tradergy shows the mid-market reference rate and does not forecast where it’s heading. For the 52-week highs and lows and a daily table, see the AUD/SAR rate history.
The other directions of this rate: the reverse rate, SAR → AUD, is on the receiving Saudi riyal view, and sending Australian dollars to Saudi Arabia is covered on the AUD → SAR transfer page. Every AUD pair sits on the convert hub, and to work in more than one currency at once there is the currency converter.
What SAMA publishes about the peg
The Saudi Central Bank publishes the riyal's anchor as a commitment, and it has published a statement affirming it - an act worth noticing in itself, since a central bank does not ordinarily need to reaffirm an arrangement nobody is asking about. That statement calls the peg "a strategic choice that has supported economic growth in Saudi Arabia for over three decades", names the official rate of 3.75 riyals to the US dollar, and describes it as an anchor of monetary and financial stability. The Bank's own history page records its statutory role as formulating and implementing monetary policy and issuing the currency.
The way it evidences the commitment is worth noticing, because most central banks reach for a ratio and this one reaches for a duration. In the same statement SAMA gives its reserve cover as 43 months of imports - not a percentage of the money supply or of short-term external debt, but the number of months the country could go on buying from abroad. It is a claim about how long the country could keep buying.
For anyone converting from Australia the consequence is arithmetic. Because the riyal is held at a single administered number against the US dollar, the Australian dollar to riyal cross moves with the Australian dollar against the US dollar and very little else. A reader watching this pair is, in practice, watching a different one.
At the border the rule is a declaration. The Zakat, Tax and Customs Authority requires travellers to declare currencies, bearer negotiable instruments, gold bars, precious metals, gemstones and jewellery worth 40,000 riyals or more, or the equivalent in foreign currency.
Sources: Saudi Central Bank, SAMA affirms commitment to exchange rate policy · Saudi Central Bank, our history · Zakat, Tax and Customs Authority, customs declaration for travellers