How big is the largest cockroach in the UK?

The largest cockroach species found in the UK is the Giant Burrowing Cockroach (Macropanesthia rhinoceros), which can grow up to 10 centimeters (about 4 inches) in length. This species is native to Australia but can occasionally be found in the UK as a pet. In general, the common cockroaches in the UK, like the German and American cockroaches, are much smaller, typically measuring around 2 to 4 centimeters.