Man orders size 14.5 slipper and gets size 1,450Tom Boddingham, 27, has a size 13 right foot while his left is slightly bigger measuring a size 14 and a half.
When he ordered his custom slipper, the manufacturers in China misread "size 14.5" and instead built a size 1,450 measuring 7ft long.
Mr Boddingham, who has always worn custom made shoes, said he now plans to sell the giant slipper on eBay.
He said: "It was sent directly from Hong Kong and measures 210 x 130 x 65cms - the same length as a grizzly bear or a family car.
"I reckon I must be the owner of the biggest slipper in the world.
"I'm going to sell it online and if I can make a few quid out of it then all the better."
A company spokesman for Monster Slippers apologised to Tom, from Ilford, in east London, and said the mistake occurred because of a translation error.
The spokesman said: "We have apologised to Mr Boddingham and are making him a replacement slipper of the right dimensions."
A spokesman for the factory said they thought the slipper was for a shop window display.