DETROIT -

Shopping for airline tickets can be quite a roller coaster ride. Prices go up, prices go down, how do you know the right time to lock in the best fare?

Some travel websites have started adding "Price Predictors" to help you estimate if you're making that purchase at the right time. 

Here's how it works: the new tool crunches the data and analyzes pricing models to predict whether the current price of a ticket or hotel room is likely to rise or fall. After the analysis, the predictor gives you a percentage that predicts how likely it is that you'll see a change in the price.

Then, you can make your best estimate on whether it’s the right time to buy, or if you should wait awhile longer. 

The hotel booking site "The Suitest" has added this price forecasting to its website. In January, Kayak added this option to its website, but it allows guests to predict if they think the price will go up or down. It's like asking a few hundred of your best friends to help you decide the right time to buy.

Experts say its similar to what financial experts do, processing large amounts of information to make decisions on whether to buy or sell stocks.