Don't even try to measure your insole, you'll never get it right. Just look at the measurements on any of your sneakers in CM or CHN. Then take that information and find the corresponding US size in the size guide. For example, the insole length of 25 CM corresponds to US 7 in Vans. You may get a different US size with a different brand due to slightly different measuring.
Guess (also known as GUESS?) is a global fashion company that offers clothing and accessories for men, women and children. The company is represented in many countries including the Czech Republic, where it sells products such as watches, jewelry and perfumes. Guess also owns the luxury brand Marciano, which focuses on the more upscale market. The founders of Guess are four brothers from Marseille, France: Georges, Armand, Paul and Maurice Marciano. They emigrated to California in 1977 and launched their signature product in 1981: a pair of three-zip jeans called "Marilyn" (Style #1015). These jeans were initially rejected by many retailers, but became a hit after they were shown in Bloomingdale's stores. The Guess brand is known for its black and white ad campaigns featuring famous models such as Claudia Schiffer, Eva Herzigova and Laetitia Casta. Interestingly, in the film Back to the Future, the main character Marty McFly (played by Michael J. Fox) wore a special Guess denim outfit designed for the film. The brand represents a fusion of American and European influences, expressing youthfulness, sensuality and courage.