For the best travel deal book 54 days in advance says CheapAir.com

IT’S the airlines little secret and now it’s all yours. We reveal why the number 54 will get you the most bang for your buck.

Get in early and take off.

BOOKING a flight is often confusing, annoying and frustrating. Prices fluctuate so frequently that most travellers can't tell if they are getting a good deal.

We check multiple websites, often several times a day. Then, a few days after we finally do book that non-refundable ticket, there's a sale, confirming that we overpaid.

So when is the best time to book a flight?

One travel site dug through the data and has an answer for us: 54 days in advance. Well, except there are plenty of caveats.

These travellers remembered magic number 54.

We'll get back to that number in a minute, but first a little bit about how the process works.

Airlines use sophisticated computer programs to analyse booking trends and constantly change prices to get the most money out of each flight.

That's why two passengers in the same row might have paid vastly different fares, depending on when they booked.

Complicating matters is a bevy of fees added to help the airlines offset higher jet fuel prices.

That's why booking at the right time is so much more important today.

That brings us to 54 days.

Don't be grounded by sky-high airfares.

For a study published in February, booking site CheapAir.com looked at millions of trip combinations, searching as far as 320 days in advance to one day prior to departure and every possible day between. That's 1.3 billion airfares.

The result: 54 days in advance was the best time, on average, to buy domestic tickets. This is not a hard-and-fast rule, however.

Airfares to popular holiday destinations tend to go up sooner. Think flights to Bali, New Zealand and Europe.

That's why CheapAir tried to simplify things and come up with a more-general rule: The prime booking window is 29 to 104 days before departure.

Now, here's some bad news: The formula is completely different for those peak travel periods when everybody wants to fly.

So, if you still haven't booked your flights for a European summer, forget about it. The best time to buy those, according to CheapAir, was a whopping 319 days in advance.

But at least you can start thinking now about Christmas travel. The cheapest day to book those flights was June 4, around six months prior.

Winners are grinners.

Here are some other tips to saving:

— Look for connecting flights. Flying non-stop is ideal, but that convenience isn't free. Adding one stop could save $100 round-trip. Just leave plenty of time to connect.

— Be flexible with your dates. Use a flexible date search to find the cheapest days in a month to fly.

— After 24 hours, still watch for price declines. Any savings is typically wiped out by fees to change your reservation, ranging from $75 to $200.

Happy campers.

— Book intra-Europe flights through overseas websites. The flights are often cheaper on the airline's home country website. Google's Chrome browser will translate it for you.

If that doesn't work, try the country specific site of travel sites and airlines.

— Pick two different airlines. Most airlines now sell one-way flights at reasonable prices. One airline might be cheaper for the outbound flight and another for the return.

— Search multiple sites. The cheapest flight doesn't always show up on every website. Look at airport websites to make sure you aren't missing a carrier.

— Fly, then drive. Some airlines have a virtual monopoly at certain airports, allowing them to charge more. Most search sites can check fares at airports 50, 75 or even 100 kilometres from your destination.