Ever felt your Big Mac meal was more/less expensive last time round, but you're too drunk to be certain? McDonald's aficionado Tom Ravenscroft decided to scoff his face do some serious research, visiting 57 branches of the fast food chain within the M25, and recording the prices at each.
Then he made this map:
Just like a Big Mac itself, the results are bafflingly tasty.
Says Ravenscroft, "My assumption was that I would find two price points that would broadly divide the city into a doughnut: either with reduced prices in the suburbs surrounding higher ones in the centre, or vice versa."
Not so. Not only does the map reveal an array of Big Mac meal price points, but they don't always appear in the areas of London you'd expect them too.
While relatively affluent Greenwich has London's cheapest Big Mac meal (£4.09), Romford shopping centre is in the steepest price bracket (£4.69).
And if you're thinking the chain is targeting less affluent/competitive areas with higher prices, that doesn't seem to be the be the case either: Victoria station (affluent, well-connected) also has a £4.69 Big Mac meal, while in Kingston it's just £4.39.
"Prices do not seem to be more expensive in zone 1 than the suburbs," says Ravenscroft. "While the majority of central McDonald's are priced at £4.49 and £4.59, many others are not.
"Overall," he concludes, "it is almost impossible to determine a board pattern or even rules."
So far, the map only covers about 30% of London's McDonald's. Ravenscroft now wants your help completing it. If you visit a London branch of the chain which doesn't feature on the map, please report the price of a Big Mac meal via the McMapping the City website, or tweet @tomravenscroft