Side by side in the photo below is a very large Megalodon Tooth at just over 6 inches long and a replica of a near record size Great White tooth at 2 1/2 inches long.

The largest known Megalodon tooth is about 7 3/8 inches in length. There have only been a handful EVER found exceeding 7 inches. The largest confirmed great white shark teeth are less than 3 inches long. As you can see there really isn’t much of a comparison, it would be hard to confuse the two.

Another Megalodon Comparison

Here’s another tooth size comparison with a 6 5/8 inch Megalodon tooth, a 3 1/8 inch fossil Great White (they got bigger in the past) and a 1 1/2 inch modern day Great White. Photo Credit: Brandon Zulli

Other Size Comparisons

The Megalodon was estimated to reach a maximum size of 50-60 feet while the largest confirmed Great White shark is 21 feet with unconfirmed reports in the 25 foot range.
The Megalodon was estimated to weigh as much as 100 tons compared with 3 1/2 tons for the largest Great White.

Size comparison of Carcharodon carcharius (Great White), Rhincodon typus (Whale Shark), human and upper and lower estimates for Megalodon sizes. Drawing licensed under Creative Commons by Matt Martyniuk