Who this is for: anyone staring at a fare right now and trying to decide whether to buy it or wait.
How we know: Sources are listed at the end. The method uses figures rendered live on Wildly route pages (which carry their own check dates) and published rules and studies from DOT, Google and others. The worked example uses placeholder numbers, marked as such, so that nothing in this text can go stale.
"Is this a good flight price?" is a question that cannot be answered from the number alone. $780 for Seattle to Tokyo is a different proposition in February than in the first week of April, in basic economy than in main cabin, and with a checked bag than without. What you need is a reference range, a seasonal adjustment, a look at what the fare actually includes, and an all-in total. This guide gives you that as four steps you can run in ten minutes, then applies it to a real route page.
Step 1: compare to the observed range
A fare is only good relative to what the same search has cost recently. Two sources give you that:
- Google Flights price insights. Google shows "Prices are less than usual" when a fare is significantly below what it expects "based on an analysis of past prices of similar trips", and "Prices are unlikely to drop before you book" when its model is confident the fare will not fall before departure (Google Travel Help). Google does not show you the underlying numbers.
- A Wildly route page. Each route page shows the lowest economy fare found in the most recent daily check, with the check date and the sampled travel dates printed next to it. Once a route has enough daily observations, the page also shows typical, good and great bands derived from percentiles of the observed fares, together with the number of observations behind them. Wildly records daily prices on about 240 routes; route pages show observed ranges as they accumulate. The full procedure is on /methodology.
Read the band, not the single number. If the page says the bands rest on only a handful of observations, treat them as loose. If your fare is at or below the "good" band on a route with weeks of history, that is meaningful.
Step 2: adjust for season
The observed range on a route page is a rolling window; it does not know that you are flying over Golden Week or Thanksgiving. Layer the calendar on top:
- Google's 2025 analysis of fares from 2021 to 2025 found international fares lowest "49 days or more before departure", with Christmas trips lowest 51 days out (32 to 73 days is the low range) and spring break trips lowest 43 days out (28 to 61 days) (Google blog).
- If your dates sit in a destination's peak (cherry blossom in Japan, July and August in Europe, Christmas week in the Caribbean), a fare inside the route's "typical" band may be the best you will see. Our seasonality guides for Japan, the Caribbean and Europe lay out those calendars with sources.
Step 3: check the fare class
Two fares with the same dollar figure can be different products. Airlines file fares under booking codes; the code is "the first letter of a fare basis code", and booking codes "are the identifiers used by the airline's revenue management department to control how many seats can be sold at a particular fare level" (Wikipedia: Fare basis code). In practice you need to answer three questions before comparing prices:
- Is it basic economy? On many carriers that means no seat selection, no changes, and sometimes no full-size carry-on.
- Is a checked bag included? On transatlantic and transpacific economy fares it often is; on basic economy fares and many Caribbean routes it often is not.
- Is it changeable or refundable? A slightly higher flexible fare can be the better buy if your plans might move.
The fare Wildly records is the lowest Google Flights returns for the sampled itinerary, and the methodology page notes it "may be a basic economy fare with bag or seat restrictions". Compare like with like.
Step 4: total the price, including bags
US rules require that an advertised fare be "the entire price to be paid by the customer to the carrier", inclusive of government taxes and fees; optional services may be charged separately but the consumer must "affirmatively 'opt in'" to them (14 CFR 399.84). So the headline fare is honest about taxes but says nothing about bags, seats or changes. Build the total yourself:
- base fare including taxes, as displayed
- plus checked bags each way, from the airline's fee page
- plus seat selection if you need to sit together
- plus any change fee you are likely to pay
Then compare totals, not fares. Kayak's help page also cautions that "the price displayed may occasionally no longer be available, resulting in an outdated price" by the time you reach the booking site (KAYAK Help), so re-check the total on the airline's own page before deciding.
One more lever from Google's study: "Taking a layover helps you save about 22% on average, versus flying nonstop" (Google blog). If the fare you are judging is nonstop, a connecting fare on the same page is a different product at a different price point, and either can be the good buy depending on your time.
Worked example: Seattle to Tokyo
Open the Seattle to Tokyo route page. The numbers below are placeholders to show the arithmetic; the live page carries the real figures and their check dates.
- Observed range. Suppose the page shows a lowest fare in the latest check of $X, and bands of "great: below $A, good: $A to $B, typical: $B to $C" resting on N days of observations. Your quoted fare is $Y. Locate $Y in those bands. If $Y is below $A and N is more than a few weeks, that is strong.
- Season. If you are flying in the second half of March or the first half of April, Japan's cherry blossom window, expect the route's whole range to be shifted upward relative to, say, late May. A fare in the "typical" band during blossom season can be as good as it gets.
- Fare class. Is $Y a basic economy fare? Check whether the first checked bag is included and whether the ticket is changeable.
- Total. Add any bag fees and seat fees to $Y. Compare that total against the route's "good" band, and against the connecting alternatives on the same page.
If the total sits at or below "good", the season is not peak, and the fare includes what you need, buy it. If it sits in "typical" and you have time, set a Wildly alert at the "good" threshold, with plus or minus 3 days if you can move, and turn on Google Flights tracking for the same search. The free plan covers this; details are on /pricing. The same method works on any route page, for example New York to London, Chicago to Cancun or Los Angeles to Osaka.
When the method says "wait" and when it says "buy"
- Buy when the total is inside or below the good band, Google's insight says prices are unlikely to drop, or your dates are inside a holiday peak.
- Wait with an alert when the total is in the typical band, you are more than about seven weeks out (Google's low point for international travel), and your dates are not tied to a holiday.
- Do not wait on a fare that already looks like an error; see mistake fares explained.
FAQ
Is a flight price good if Google says "prices are low"? It is a good sign. Google's label means the fare is significantly below its expectation from past similar trips. Confirm with the route page's observed bands and check what the fare includes before buying.
How much history does a route page need before the bands mean anything? The page shows how many observations sit behind the bands. Bands built on a few days are wide by construction; they tighten as the daily series grows. Read the count before you trust the band.
Should I compare fares with or without bags? With. The DOT full-fare rule guarantees taxes are in the headline number, not bags. Two fares $60 apart can swap order once a checked bag each way is added.
Does a connection make a fare "worse"? It makes it a different product. Google's study found connecting itineraries about 22 percent cheaper on average than nonstops. Whether that trade is worth it is your call, but judge each against its own comparables.
Sources
- 14 CFR 399.84, Price advertising and opt-out provisions (Cornell LII): https://www.law.cornell.edu/cfr/text/14/399.84
- Google Travel Help: How to find the best fares with Google Flights: https://support.google.com/travel/answer/7664728
- Google blog: Holiday travel trends and insights for 2025: https://blog.google/products/search/holiday-travel-trends-2025/
- Wikipedia: Fare basis code: https://en.wikipedia.org/wiki/Fare_basis_code
- KAYAK Help: Pricing and Price Alerts: https://www.kayak.com/c/help/pricing/