--- title: "Megalodon Tooth Size Calculator: Shark Length | Fossil Wharf" description: "How big was the shark? Measure a megalodon or great white tooth in cm or inches and get the shark's length in metres and feet, with published ranges." url: https://fossilwharf.me/ --- Megalodon and great white · centimetres and inches # Megalodon tooth size calculator 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. ## How the shark tooth calculator works Pick 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. - **Crown height** uses Shimada's (2019) equation for upper front teeth of great white sharks: length in cm = 11.788 × crown height in mm + 2.143. For other mackerel sharks it uses Shimada, Becker and Griffiths' (2021) general line, 11.784 × crown height − 0.331 (r² = 0.880), which they describe as conservative. - **Crown width** follows Perez, Leder and Badaut (2021): the width is divided by the share of one jaw quarter's summed crown width that its position makes up, and the result is scaled by 26 measured jaw quarters of modern great whites. The range shown is the spread across those jaws. For megalodon it averages their adult and juvenile models, as the paper recommends. 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. ## Sources 1. Shimada K. 2019. The size of the megatooth shark, Otodus megalodon (Lamniformes: Otodontidae), revisited. Historical Biology 33(7):904–911. [doi:10.1080/08912963.2019.1666840](https://doi.org/10.1080/08912963.2019.1666840). The upper-front-tooth equation is quoted from Shimada K, Maisch HM, Perez VJ, Becker MA, Griffiths ML. 2023. Historical Biology 35(2):208–217. [doi:10.1080/08912963.2022.2032024](https://doi.org/10.1080/08912963.2022.2032024). 2. Shimada K, Becker MA, Griffiths ML. 2021. Body, jaw, and dentition lengths of macrophagous lamniform sharks… Historical Biology 33(11):2543–2559, Table 2, line f. [doi:10.1080/08912963.2020.1812598](https://doi.org/10.1080/08912963.2020.1812598). 3. Perez VJ, Leder RM, Badaut T. 2021. Body length estimation of Neogene macrophagous lamniform sharks (Carcharodon and Otodus) derived from associated fossil dentitions. Palaeontologia Electronica 24(1):a09, Tables 2–3 and Appendices 3–5. [doi:10.26879/1140](https://doi.org/10.26879/1140). The default tooth is the upper left A2 of UF-VP-311000 (Yorktown Formation, North Carolina): crown height 96.6 mm, crown width 101.2 mm. 4. Shimada K, Motani R, Wood JJ, et al. 2025. Reassessment of the possible size, form, weight, cruising speed, and growth parameters of the extinct megatooth shark, Otodus megalodon. Palaeontologia Electronica 28(1):a12. [doi:10.26879/1502](https://doi.org/10.26879/1502). 5. Unit conversions are exact: 1 inch = 2.54 cm and 1 foot = 0.3048 m (NIST Special Publication 811). Species without a published tooth-to-length method, such as tiger, bull or snaggletooth sharks, are left out. ## More fossil tools - [Geologic time scale](https://fossilwharf.me/geologic-time-scale/): The official ICS chart, zoomable, with a “how old is it?” finder. - [Deep time calendar](https://fossilwharf.me/deep-time-calendar/): Earth's history as one year, or along a walk or a toilet roll. - [Fossil identifier](https://fossilwharf.me/fossil-identifier/): A four-question key for beach fossils and lookalikes, with a printable sheet. - [Fossil collecting rules](https://fossilwharf.me/fossil-collecting-rules/): UK and US codes, what you may keep, and a tide and cliff checklist. - [Radiometric dating calculator](https://fossilwharf.me/radiometric-dating-calculator/): Carbon-14, potassium-argon, uranium-lead and rubidium-strontium ages. - [Dinosaur size comparison](https://fossilwharf.me/dinosaur-size-comparison/): Up to four prehistoric animals to scale beside a person. ## Recommended for fossil hunters ### CleanTempMail Fossil clubs, shops and printable ID sheets sometimes ask for an email address before a one-off download. CleanTempMail gives you a free temporary inbox at once, with no sign-up, and deletes its emails after three days. Keep your real address for museum memberships and booked fossil walks. [Get a temporary inbox](https://cleantempmail.com/) ### WebTraceCheck Megalodon teeth and ammonites are sold all over the web. Before you pay an unfamiliar shop, WebTraceCheck's free DNS and domain lookup shows how old its domain is, and its disposable cloud browser lets you open the site on an isolated desktop that is deleted afterwards. [Try WebTraceCheck](https://webtracecheck.com/) ## Questions **How big was megalodon?** 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). **Why do the two methods give different lengths?** 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. **Can I use the slant height a seller quotes?** 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. **When did megalodon live?** 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.