# Carats to Long Tons (ct to long tn) Source: https://www.unitconvertercalculator.com/weight/carats-to-long-tons/ **1 ct = 1.9684130552221E-7 long tn** One carat equals approximately 1.968 x 10-7 long tons. The long ton (also called the imperial ton) weighs 2,240 pounds or about 1,016.05 kilograms, making it roughly 5,080,234 carats. This is one of the most extreme weight conversions between gemological and industrial units - a single long ton of diamonds would represent a staggering fortune. ## Formula Apply the conversion factor ## Conversion Table | Carats (ct) | Long Tons (long tn) | |---|---| | 10000 ct | 0.0019684130552221 long tn | | 50000 ct | 0.0098420652761106 long tn | | 100000 ct | 0.019684130552221 long tn | | 500000 ct | 0.098420652761106 long tn | | 1000000 ct | 0.19684130552221 long tn | | 2500000 ct | 0.49210326380553 long tn | | 5000000 ct | 0.98420652761106 long tn | | 10000000 ct | 1.9684130552221 long tn | | 25000000 ct | 4.9210326380553 long tn | | 50000000 ct | 9.8420652761106 long tn | ## Units ### Carat (ct) A carat is a unit of mass equal to exactly 200 milligrams (0.2 grams), used for measuring gemstones and pearls. Adopted internationally in 1907 by the Fourth General Conference on Weights and Measures. ### Long Ton (long tn) A long ton (imperial ton) is a unit of mass equal to exactly 2,240 pounds or 1,016.0469088 kilograms. It is used primarily in the United Kingdom for shipping and naval displacement. ## Background Global annual diamond production is roughly 130 million carats, which equals only about 25.6 long tons of physical weight. A single long ton of gem-quality diamonds would be worth tens of billions of dollars. The long ton was traditionally used for British coal, iron, and shipping cargo - bulk materials that are the polar opposite of precious gemstones in both density of value and method of handling. ## Good to Know The long ton originated in medieval English commerce as 20 long hundredweights (20 x 112 = 2,240 pounds). Its name derives from the Old English 'tunne,' a large cask used for shipping wine. The irony of converting this bulk cargo unit to the carat - a unit born from individual carob seeds - captures the full range of human measurement, from the heaviest industrial loads to the lightest precious objects. ## FAQ ### How many carats are in one long ton? One long ton contains approximately 5,080,234 carats. This is calculated from 1 long ton being 1,016.047 kilograms and 1 kilogram equaling 5,000 carats. ### What is the difference between a long ton and a metric ton? A long ton is 2,240 pounds (1,016.05 kg), used historically in British Commonwealth countries. A metric ton (tonne) is exactly 1,000 kg. The long ton is about 1.6% heavier than a metric ton. ### Is the long ton still in use? The long ton is largely obsolete, replaced by the metric tonne in most international trade. It still appears occasionally in British shipping records, US naval terminology (displacement tonnage), and some petroleum industry measurements. ## Non-Frequently Asked Questions ### What would happen if you dropped a long ton of diamonds? A long ton of diamonds (over 5 million carats) would weigh 1,016 kg and occupy roughly 288 liters - about the size of a large bathtub. Dropping it would create a spectacular shower of gems, a very expensive cleanup job, and an insurance claim that would make underwriters weep. ### Could a ship carry its displacement weight in diamonds? A typical cargo ship displaces about 50,000 long tons. Converting that to diamonds gives about 254 billion carats, which is roughly 2,000 years of global diamond production. The ship could physically carry the weight, but assembling that many diamonds is another matter entirely. ### Is a long ton of feathers heavier than a long ton of diamonds? They weigh exactly the same - 2,240 pounds each. But the diamonds would fit in a large bathtub while the feathers would fill several rooms. This is the classic trick question, and the answer is always the same regardless of which material you choose. ## Related Articles - [Why We Measure: The Deepest Urge in Human Civilisation](https://www.unitconvertercalculator.com/blog/why-we-measure) - [The Map Is Not the Territory: Why Every Measurement Is Wrong](https://www.unitconvertercalculator.com/blog/the-map-is-not-the-territory) - [Zero: The Most Dangerous Number in Measurement](https://www.unitconvertercalculator.com/blog/zero-the-most-dangerous-number-in-measurement) - [The Kilogram Problem: The Object That Was Its Own Definition](https://www.unitconvertercalculator.com/blog/the-kilogram-problem) - [The Body as a Ruler: Every Measurement Unit That Came From Us](https://www.unitconvertercalculator.com/blog/the-body-as-a-ruler) - [Why Your Recipe Is Lying to You: The Chaos of Cooking Measurements](https://www.unitconvertercalculator.com/blog/why-recipe-measurements-are-unreliable) - [15 Obscure Measurement Units You've Never Heard Of (But Still Need)](https://www.unitconvertercalculator.com/blog/obscure-measurement-units-guide) - [When Measurements Go Wrong - Disasters, Blunders and Happy Accidents](https://www.unitconvertercalculator.com/blog/when-measurements-go-wrong) - [The Surprising Stories Behind Everyday Units of Measurement](https://www.unitconvertercalculator.com/blog/stories-behind-measurement-units) - [Metric vs. Imperial - The Complete Guide to the World's Two Measurement Systems](https://www.unitconvertercalculator.com/blog/metric-vs-imperial-complete-guide) - [Understanding Weight Units - Kilograms, Pounds, Stones & Ounces](https://www.unitconvertercalculator.com/blog/understanding-weight-units) - [Complete Baking Measurement Guide - Cups, Grams, Ounces](https://www.unitconvertercalculator.com/blog/baking-measurement-guide) ## See Also - [Long Tons to Carats](https://www.unitconvertercalculator.com/weight/long-tons-to-carats/)