A snail can travel up to approximately 0.66 inches per minute. This speed was determined in a study published in 2012 by the University of Exeter in England.
Researchers of the study clocked the snail's maximum speed at approximately 0.66 inches per minute (1.67 centimeters per minute), concluding that they can travel up to around 82 feet (25 meters) in 24 hours.
The study used a sample size of 450 garden snails, tracking the speed, distance and locations to which they traveled within a 72-hour period. To track the snails' movements, researchers mounted LED lights on top of some of the snails' shells and others were painted with UV paint. The paths the snails took were easily measured using time-lapse photography.
This study was performed to increase awareness and try to prevent the spread of lungworms—parasites found in snails that are possibly fatal to dogs that eat the snails.