There is no single number. The required saving ranges from about €7 to over €100 — depending on which airports you are comparing. Whether the saving is personally worth the extra journey time — that part is yours.
Three verified London airport pairs · Heathrow, Gatwick, Stansted · Jul 2026
The alternative airport may have a cheaper ticket. But it often has higher fixed costs — more expensive baggage, seat fees, or airport transfer. The flight must save enough to overcome that difference. How much “enough” is depends on the airport pair.
In the canonical Travelvus scenario, the Stansted flight would need to save more than €101 to overcome its higher baggage and transfer costs. At the observed €68 saving, it still loses by €33 on total cost. This is not a permanent threshold.
Full comparison →In the canonical Travelvus scenario, the LHR flight would need to save more than €7. But LHR typically costs €20 more — so Gatwick holds for most destinations. The margin moves with your London destination. This is not a permanent threshold.
Full comparison →At the canonical €20 saving, Stansted just wins — by €4 net. A margin thin enough that personal judgment matters more than arithmetic. This is not a permanent threshold.
Full comparison →These break-even thresholds are derived from Travelvus production scenarios using verified transfer costs for three London airports (Heathrow, Gatwick, Stansted), walk-up contactless/Oyster fares, and GBP→EUR at 1.17. They are not universal thresholds — different flight prices, baggage policies, or destinations produce different break-evens. Travelvus does not yet have verified transfer data for Luton, London City, or Southend.
Different airports have different fixed-cost profiles. The spread ranges from about €7 to over €100.
Where in London you are going changes the transfer cost. This moves the break-even within the same airport pair.
Baggage fees differ by airline and airport. Removing baggage changes the fixed-cost difference and can shift the break-even point.
Fixed costs scale with group size. The break-even per person stays the same — but the total saving grows with each additional traveller.
Even within one airport pair, your London destination can move the break-even. For Heathrow vs Gatwick: at Victoria, LHR needs to save >€7. At Paddington with advance HEX fares, the two airports nearly tie. The break-even is not fixed — it moves with where you are going.
Travelvus can calculate how much cheaper a flight must be to overcome an alternative airport’s higher fixed costs.
It cannot decide whether a €4 net saving is worth 20 extra minutes on a train. It cannot decide whether simplicity matters more than a narrow cost advantage.
When the numbers are too close, or when time and friction enter the equation, Travelvus hands the decision to you.