Four things drive RTW price: number of stops, total distance, cabin class, and timing. More stops and more distance cost more. Business class adds 2-3x. Peak season (June-August, December) runs higher than shoulder months. Booking 3-11 months out gets better fares.
Several factors push RTW ticket prices up or down. Understanding them helps you make trade-offs that match your budget.
Number of stops matters, but not the way most people think. Adding a stop that falls naturally along your route might cost nothing extra, or even reduce the cost. Flying from Asia to Europe with a stop in Dubai or Istanbul is basically free because you're connecting through those hubs anyway. But adding a stop that requires a detour (like going from Tokyo to Sydney and then up to India) adds distance and cost.
Direction of travel affects pricing because airline availability isn't symmetrical. The same route can cost $500 to $1,000 less going eastbound versus westbound, or vice versa. AirTreks prices both directions and recommends the better deal. We have databases of "airline geography" that often does not map to real world geography to make routes work.
Class of service is the biggest single variable. Business class on long-haul flights costs 3 to 5 times more than economy on the same route. A mixed-cabin approach (business on the long legs, economy on the short ones) is a common way to manage this.
Season and advance purchase work together. Peak travel periods (June through August, December holidays) see higher fares because demand is up and discount inventory sells out faster. Booking 6 to 11 months ahead generally secures the best pricing. Under 8 weeks out, expect to pay a premium.
Routing efficiency is where AirTreks earns its keep. Backtracking (going east and then west and then east again) costs more than moving in one general direction. Using major airline hubs as connection points keeps fares lower. Knowing which airlines offer the best pricing on specific routes, and which fare classes to combine, is the kind of expertise that saves hundreds or thousands of dollars on a complex itinerary.
Total distance is a factor on alliance tickets, which price by mileage tiers. AirTreks builds custom tickets that aren't bound by mileage formulas, which often results in better pricing for routes that cover a lot of ground.