Your trip
65 US airports across all major metros.
41 destinations grouped by region.
Fill in your trip — we'll show which booking window saves the most.
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How we got these numbers
Domestic and international booking windows come from Google's 2021-2025 flight pricing study and Expedia's 2026 Air Hacks for Six report. Holiday windows come from Expedia's holiday travel breakdown and Going.com's 2026 fare trend data. Penalty ranges (10% early premium, 35% late-booking premium, 13% in-window savings) reflect average deviations in the same public datasets.
When to Book — Common Questions
How far in advance should I book flights?
The sweet spot for domestic flights is 3 to 5 weeks out, based on 2026 ARC and Hopper data. For international, book 2 to 6 months ahead. Holiday travel (Thanksgiving, Christmas, spring break) requires 3 to 6 months' lead time — prices spike fast as seats fill.
Do flight prices go down closer to the departure date?
Generally no. Last-minute prices are higher, not lower, except for rare distressed-inventory sales. Prices typically dip in the 3–5 week window and then rise again. The calculator tells you whether you are inside the sweet spot or outside it for your specific travel date.
What is the cheapest day to book flights?
Day of week matters less than booking window. Tuesdays and Wednesdays occasionally show small discounts — typically under 5% — as airlines adjust pricing. The booking window (days before departure) has a much larger effect on price than what day you book.
When is the best time to book a cruise?
Cruises follow a different curve. Best prices are either very early (12–18 months out, especially during Wave Season January–March) or last-minute (within 30 days of sailing, with limited cabin choice). This calculator focuses on flights, but the same principles apply to cruise add-on airfare.