Megalodon and great white · centimetres and inches
How big was the shark that lost your tooth? Measure the crown of a fossil megalodon or great white tooth to get the shark's length in metres and feet. The default, a real North Carolina megalodon tooth, gives about 11 m by crown height and 17 m (15 to 20 m) by crown width: the two published methods disagree.
Estimated total length11.4–20.4 m (37–67 ft)
11.788 × 96.6 + 2.143 = 1,141 cmsummed crown width 101.2 ÷ 0.092 and ÷ 0.095, scaled by 26 modern jawsPick the shark and the tooth's place in the upper jaw, then measure the crown with a ruler or calipers. Use upper teeth: Perez et al. (2021) found the upper half of a dentition gives the most reliable lengths, and Shimada (2019) prefers upper front teeth. Upper teeth are broad triangles; lower teeth are narrower, with a more robust root.
Front (anterior) teeth are always the tallest in these sharks, so the tallest teeth in a set are probably an A1 or A2. If you are not sure of a tooth's position, try two or three and compare.
Species without a published tooth-to-length method, such as tiger, bull or snaggletooth sharks, are left out.
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The largest museum teeth give 14.2 to 15.3 m (47 to 50 ft) by crown height (Shimada 2019) and about 20 m (66 ft) by crown width (Perez et al. 2021). Vertebrae suggest it possibly reached about 24.3 m (80 ft) (Shimada et al. 2025).
Crown height is compared with great white teeth one tooth at a time; crown width is scaled from the summed widths of whole jaws. Perez et al. (2021) found the crown-height method gives lower lengths for megalodon, but within half a metre for great whites.
No. Slant height runs along the longest edge, so it is longer than the crown height these equations use. Measure the crown height and width yourself, as in the drawing.
About 23 to 3.6 million years ago, says the Florida Museum of Natural History. Boessenecker et al. (2019) put its extinction at about 3.6 million years ago, at the early to late Pliocene boundary.