This is a visual representation of the difference in size between a blue whale and an African elephant. It has to be approximate. The existing illustrations online are a little vague and some are possibly misleading.
On my estimate and research elephants are around 4 meters to 5.5 meters long excluding the extended truck and extended tail. The blue whale can be around 100 feet in length at a maximum which is 33 meters. 30 meters (whale) divided by 5 meters (elephant) is 6. The blue whale is about 6 times the length of the elephant at a rough calculation.
I have used this calculation to create the image below. Comments would be welcome. Obviously both whales and elephants vary in length and size but this is a starting point comparing a large elephant and a blue whale.
Below is one article on the whale and another on the elephant. There are more on both animal species on this site. Please explore using the search facility.