Ever wondered which domestic airline routes have the fullest flights? Well, there’s no need to wonder because the Australian government publishes monthly data showing the number of passengers flown on all of the main domestic air routes.

It’s fairly common knowledge that Melbourne-Sydney consistently has the most passengers of any Australian route. In fact, it’s the second-busiest air route in the world behind South Korea’s Seoul-Jeju route. In March 2023, the most recent month for which data is available, there were 4,749 flights between Melbourne and Sydney with a total of 690,000 passengers flown.

The Sydney-Brisbane route comes in second, followed by Melbourne-Brisbane. That’s why airlines refer to these three routes as the “golden triangle”!

Here’s a full list of the top 10 busiest Australian domestic air routes as of March 2023:

1. Sydney-Melbourne
2. Sydney-Brisbane
3. Melbourne-Brisbane
4. Adelaide-Melbourne
5. Gold Coast-Sydney
6. Gold Coast-Melbourne
7. Melbourne-Perth
8. Adelaide-Sydney
9. Sydney-Perth
10. Hobart-Melbourne

But which flights have the highest load factors, or percentage of seats sold?

The routes with the fullest (and emptiest) flights

In addition to the total number of passengers flown, the government releases monthly data showing the load factors on domestic routes with more than one airline operating.

Admittedly, routes served by only one airline are not shown. We don’t really know how many passengers there are on routes like Canberra-Perth (served only by Qantas) or Sydney-Parkes (a Rex monopoly), as these routes aren’t counted in the figures. But we do have statistics on the major domestic routes that are served by at least two airlines.

Of the routes with data available, Adelaide-Gold Coast had the highest average load factor in March 2023. On the other end of the scale, Sydney-Armidale had the highest proportion of seats left empty.

Below are the domestic routes with the fullest flights for the most recent 12-month period with data available. For comparison, we’ve also listed the average industry load factor for the same month across all Australian domestic routes.

Australian domestic routes with the highest load factors

Adelaide-Gold Coast had the highest load factors for four of the last 12 months. Trans-continental flights from Perth to the east coast also feature heavily. And it’s perhaps not surprising that so many Melburnians travelled to Cairns during the winter months of June and July.

Australian domestic routes with the lowest load factors

Most of the routes with lower load factors are to regional destinations. And with the exception of Brisbane-Hamilton Island, none of the above routes are served by a low-cost carrier. Budget airlines tend to sell more seats by offering cheaper fares.

Load factors don’t necessary equal profitability

Of course, load factors are not the only measure of a route’s success. High load factors certainly help, but they don’t necessarily mean a route is more profitable for an airline than another with a lower load factor.

Any airline can get to 100% load factors by dropping airfares low enough. But selling one seat for $400 is more profitable than selling five seats for $75. So, you also need to consider the yield on a route – which is often higher on regional routes served by turboprop aircraft compared to capital city routes.

Matt Graham

The editor of Australian Frequent Flyer, Matt's passion for travel has taken him to over 90 countries… with the help of frequent flyer points, of course!
Matt's favourite destinations (so far) are Germany, Brazil & Kazakhstan. His interests include aviation, economics & foreign languages, and he has a soft spot for good food and red wine.

You can connect with Matt by posting on the Australian Frequent Flyer community forum and tagging @AFF Editor.