Every “what time should I leave?” has the same shape: bag-drop deadline, minus honest journey time, minus margin. Here's that arithmetic done properly for all six airports — the numbers below assume pre-dawn's empty roads, which is the one mercy early flights grant.
We do the arithmetic; you do the sleeping
Long-haul: 60 min before departure. Short-haul: 45. Ryanair & Wizz: a strict 40 — treat it as law. Hand-luggage-only with online check-in works to gate close (~30 min) instead.
From central London on empty roads: Heathrow 35–50 min · Gatwick 55–75 · Stansted 55–70 · Luton 45–60 · LCY 20–35 · Bristol ~2.5 hrs. Local pickups scale down accordingly — we quote your postcode's band exactly.
15 minutes, non-negotiable — for the kerb-to-desk walk, the trolley hunt, the one roadworks diversion. Margin is what turns a sprint into a coffee.
Central London pickups shown; every worked answer scales to your postcode when you book.
Bag-drop by 04:45 → leave central London 03:45–04:00. Surrey and Sussex villages: 04:15–04:30. Full options on the Gatwick early-morning page.
Terminal by 05:30 → central London pickup 04:40–05:00. Terminal confirmed at booking — T4 and T5 are far apart with a clock running. Details on the Heathrow page.
Inside by 05:15 (strict 40-minute bag-drop) → leave central London 04:00–04:15; Essex and Herts later. The Stansted page covers the coach alternative honestly.
The brutal one: inside by 04:20 → central London pickup 03:15–03:30; Luton and Harpenden locals a merciful 03:45–04:00. Door-to-terminal beats the train+DART double timetable — see the Luton page.
Kerb by 05:45 → Square Mile pickup 05:15, Canary Wharf 05:20 — LCY's tiny terminal does the rest. First-DLR caveats on the LCY page.
Bag-drop by 05:00 → Bristol city pickup ~04:15; from London, a ~01:45–02:00 departure on empty motorways. Flyer first-service honesty on the Bristol page.
Postcode + flight number = pickup computed with margin, fare fixed, alarm justified.