What Time Should I Leave for My Flight
Your deadline is not the departure time. It is the bag drop cut-off, which can be ninety minutes earlier, and everything else is arithmetic from there.
Almost everyone plans from the wrong number
Ask someone what time their flight is and they will tell you the departure time. Ask them what time they need to be at the airport and they will usually convert that into a vague two hours. Both numbers are the wrong place to start, because neither is the moment at which your options close.
The moment that matters is the bag drop cut-off. For a short-haul flight that is commonly forty to sixty minutes before departure, and for long-haul it can be sixty to ninety minutes or more, depending on the airline and the destination. Miss it and the flight leaves without you even though the aircraft is sitting there and the departure time has not arrived. It is the single most unforgiving deadline in the whole journey.
Once you anchor on that, the calculation becomes mechanical. Bag drop cut-off, minus the time you want in the terminal before it, gives you an arrival target. Arrival target, minus a realistic journey time, minus a traffic buffer, gives you a pickup time. That is the number to book, and it is usually earlier than instinct suggests.
The part people compress is the buffer, because it feels like wasted time. It is not wasted, it is insurance priced in minutes. Thirty minutes of buffer costs you thirty minutes of sitting in a terminal. Not having it costs a flight, a hotel night and a replacement ticket, and the exchange rate on that trade is not close.
Working backwards from your departure time
Indicative planning guidance. Airline cut-offs vary significantly, so always check the specific times for your carrier and destination.
| Step | Short-haul | Long-haul |
|---|---|---|
| Gate closes before departure | 20 to 30 min | 30 to 45 min |
| Be at the gate by | 40 min before | 60 min before |
| Allow for security and passport control | 30 to 45 min | 45 to 60 min |
| Bag drop typically closes | 40 to 60 min before | 60 to 90 min before |
| So be inside the terminal by | 2 hours before | 3 hours before |
| Add your journey time | See the worked examples | See the worked examples |
| Add a traffic buffer | 30 min | 30 to 45 min |
| That is your pickup time | Book it | Book it |
Worked pickup times for a 09:00 Heathrow departure
Assumes a short-haul flight, in terminal by 07:00, and uses the upper end of the journey estimate plus a thirty minute buffer. Deliberately conservative, since early morning roads are usually quieter.
| Pickup area | Typical journey to Heathrow | Suggested pickup |
|---|---|---|
| Ealing, W5 | 30 to 50 min | 05:40 |
| Kingston, KT1 | 35 to 55 min | 05:35 |
| Watford, WD17 | 40 to 65 min | 05:25 |
| Camden, NW1 | 45 to 75 min | 05:15 |
| Croydon, CR0 | 55 to 85 min | 05:05 |
| Canary Wharf, E14 | 60 to 95 min | 04:55 |
| Dartford, DA1 | 60 to 95 min | 04:55 |
The five minute version of the calculation
Do this once and you will never guess again.
Find your bag drop cut-off, not your boarding time
It is on the airline website against your route, and it differs between carriers and destinations. If you are travelling hand luggage only, use the gate closing time instead, which is also earlier than the departure time.
Set an in-terminal target
Two hours before departure for short-haul, three for long-haul. Add thirty minutes if you are travelling with children, checking sports equipment, needing assistance, or flying at a peak hour from a busy terminal.
Get a realistic journey time for the actual hour
A route that takes thirty five minutes at five in the morning can take seventy five at eight. Use the time you will actually be travelling, not a general estimate, and ask the operator rather than assuming.
Add thirty minutes of buffer and stop negotiating with yourself
This is the step everybody erodes. Keep it. It absorbs a road closure, a slow forecourt, a queue at bag drop, or a passenger who cannot find their passport.
Book the pickup and get it confirmed in writing
A confirmed pickup time removes the last variable, which is you. If the number looks uncomfortably early, that is the calculation working correctly rather than the calculation being wrong.
When to add even more time
Four situations that break the standard numbers.
School holidays and Friday evenings
Both roads and terminals load at the same time. Security queues in particular lengthen sharply at the start of a holiday period, and the queue is the part of the journey you cannot influence at all.
Travelling with children or a buggy
Everything takes longer, from getting into the car to clearing security. Twenty to thirty additional minutes is realistic, and it converts a stressful morning into an ordinary one.
A known closure or event day
Marathon Sunday, carnival weekend, a ceremonial closure or major roadworks each need a different route rather than a bigger buffer. Tell the operator the date so it is planned rather than discovered.
Winter weather in the forecast
Snow and ice affect roads far more than aircraft, so the road side is where the extra time belongs. Sixty to ninety minutes is the sensible addition, along with a pickup point on a treated main road.
Related airport timing guides
Terminals, connections, delays and weather.
Airport connection time guide
How much time to leave between legs of a journey.
Wrong terminal, what to do
Inter-terminal transfer times and how to avoid needing them.
Bad weather airport transfers
Which weather affects roads and which affects flights.
Boot space and luggage guide
Getting the vehicle size right before the morning of the flight.
Will my taxi wait if my flight is delayed
How flight tracking and waiting allowances work on arrivals.