For one person travelling light, the train can win on Gatwick and roughly tie on Heathrow. For two or more people, or anyone with a suitcase and a 5am start, a fixed-fare taxi from Dartford usually comes out cheaper once you add up every line of the journey — not just the headline ticket.
"Just get the train" is the standard advice for anyone leaving Dartford for the airport. It's good advice — sometimes. The problem is that the train fare you see is rarely the fare you pay, and the comparison people make in their head almost never includes the parts of the trip that quietly cost the most: the connection across London, the drop-off charge, the early-morning gap when nothing's running.
So we did the boring thing and added it all up properly, door to door, for the two airports Dartford flies from most: Heathrow and Gatwick.
What the train fare leaves out
From Dartford station there's no single train to either airport. For Gatwick you're changing at least once, usually via London Bridge or East Croydon. For Heathrow it's worse — a train into London, the Underground or Elizabeth line across, and a walk with your bags at each end. None of that is on the ticket price, but all of it costs money and, more to the point, time and patience at the hour you're doing it.
Then there are the hidden line items. A peak return adds up fast. Two people doubles the ticket but not the taxi. And if a relative drops you at the station, that's free — but if they drop you at the airport terminal instead, most now charge a drop-off fee just to pull in for ninety seconds.
The taxi price is one number. The train price is six numbers, and four of them are hiding.
The numbers, roughly
Here's an illustrative door-to-door comparison for a weekday departure. Treat these as ballpark — live rail fares move around, and our fares are confirmed when you book — but the shape of it holds up.
| Travelling | Train, all-in (approx) | RushXO fixed fare |
|---|---|---|
| Dartford → Gatwick, 1 person | £25–35 | from £82 |
| Dartford → Gatwick, 2 people | £50–70 | from £82 |
| Dartford → Heathrow, 1 person | £30–45 | from £88 |
| Dartford → Heathrow, family of 4 | £90–140 | from £88 |
Indicative only. Rail figures include a typical cross-London connection; taxi fares are fixed and confirmed at booking, tolls included.
You can see where the line crosses. Solo and travelling light, the train is the value pick and we'd tell you so. But the moment there are two of you — and especially with a family and cases — one fixed fare split between everyone undercuts a fistful of tickets, with none of the lugging.
The bit the spreadsheet misses
Cost isn't the whole story at 5am. The earliest trains don't run early enough for a lot of flights, which is exactly when a car earns its keep. There's also the small matter of certainty: a fixed fare doesn't surge because it's a bank holiday, and a pre-booked Dartford taxi turns up at your door at the time you chose, tracks your flight on the way back, and waits free if you land late.
Punching in your own numbers? Get the exact fixed fare for your trip in seconds — then you can compare like for like.
Our honest take: check the live train price for your date, then get a fixed quote from us. If you're one person with a backpack, you'll probably take the train, and that's fine. If you're two-plus, or it's an awkward hour, the car usually wins on money and on the morning.