Expansion can vary depending on whether the product is Gun Grade, Hand-Held or Genius Gun. Hand-held and Genius Gun foam will expand by 150-200%, which means the joint/cavity only needs to be filled by 30-40%. If the product is Gun-Grade the foam will expand by 50-100%, meaning the joint/cavity will need to be filled by at least 50%. Expansion rate will also depend on the ambient and can temperatures, as well as humidity.
It is important to note that some formulations have been specifically developed for applications that require low expansion rates, providing linear expansion rather than volume. It is always best to check the product instructions before applying.