We've seen plenty of boastful stats about the reinvigorated Dome — apparently, it could swallow 13 Albert Halls or 10 St Paul's Cathedrals. (Scenarios not all that far fetched, considering nearly a billion quid and numerous reputations have already disappeared into its maw.)
But here's a way to judge its size for yourself. Using Google Maps, it is possible to compare London's landmarks from an aerial perspective. The shots are all from the same level of zoom.
Sort of clockwise from top-left: The O2, Wembley Stadium, Albert Hall, Gherkin, The Oval, St Paul's Cathedral, Westminster Abbey.