# Carats to Pennyweights (ct to dwt) Source: https://www.unitconvertercalculator.com/weight/carats-to-pennyweights/ **1 ct = 0.12860298627451 dwt** One carat equals approximately 0.1286 pennyweights. The pennyweight (abbreviated dwt) is a troy weight unit equal to 1/20 of a troy ounce, or about 1.5552 grams. It remains actively used in the North American jewelry trade for pricing precious metals, making the carat-to-pennyweight conversion a daily calculation for jewelers who handle both gems and gold. ## Formula Apply the conversion factor ## Conversion Table | Carats (ct) | Pennyweights (dwt) | |---|---| | 0.25 ct | 0.032150746568628 dwt | | 0.5 ct | 0.064301493137256 dwt | | 1 ct | 0.12860298627451 dwt | | 2 ct | 0.25720597254902 dwt | | 5 ct | 0.64301493137256 dwt | | 10 ct | 1.2860298627451 dwt | | 25 ct | 3.2150746568628 dwt | | 50 ct | 6.4301493137256 dwt | | 100 ct | 12.860298627451 dwt | | 250 ct | 32.150746568628 dwt | | 500 ct | 64.301493137256 dwt | | 1000 ct | 128.60298627451 dwt | | 5000 ct | 643.01493137256 dwt | ## 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. ### Pennyweight (dwt) A pennyweight is a unit of mass equal to 24 grains or 1/20 of a troy ounce (1.55517384 grams). Used in the jewelry trade for weighing precious metals. ## Background American jewelers commonly buy and sell gold by the pennyweight. A gold engagement ring setting might weigh 2 to 4 pennyweights of 14-karat gold, while its center diamond weighs 1 carat (0.1286 dwt). Scrap gold dealers quote prices per pennyweight, requiring jewelers to separate gem weight in carats from metal weight in pennyweights when calculating the value of estate jewelry. ## Good to Know The pennyweight is one of the few troy units that survived metrication in daily American commerce. While scientists and pharmacists switched to grams, American jewelers kept the pennyweight because their pricing models, scales, and trade customs were built around it. This persistence creates a distinctive American jewelry trade language where gemstones are priced per carat and metals per pennyweight - two different historical systems coexisting on the same workbench. ## FAQ ### How many pennyweights are in one carat? One carat equals approximately 0.1286 pennyweights. Conversely, one pennyweight (1.5552 grams) equals about 7.776 carats. ### What is a pennyweight and why is it called that? The pennyweight was originally the weight of a silver penny in medieval England. It equals 1/20 of a troy ounce or 24 grains (about 1.555 grams). The abbreviation 'dwt' comes from 'denarius weight,' referencing the Roman coin the English penny was modeled after. ### Is the pennyweight still commonly used? Yes, actively in the North American precious metals trade. Jewelers, gold refiners, and scrap metal buyers routinely price gold and silver per pennyweight. It is less common outside North America, where grams are preferred. ## Non-Frequently Asked Questions ### If I traded a carat of diamond for a pennyweight of gold, who wins? A pennyweight of gold (1.555 g) at mid-2020s prices costs roughly 90 to 120 dollars. A 1-carat diamond of decent quality costs 4,000 to 10,000 dollars. The person receiving the diamond wins by a factor of 40 to 100. The gold-for-diamonds trade has never been a fair one by weight. ### Why does the pennyweight abbreviation use 'd' instead of 'p'? The 'd' comes from 'denarius,' the Roman silver coin that the English penny was based on. This is the same reason the old British pre-decimal penny symbol was 'd' (as in '6d' for sixpence). The pennyweight is thus abbreviated 'dwt' for 'denarius weight' - a linguistic relic of the Roman Empire surviving in modern American jewelry shops. ### How many engagement rings worth of gold does a carat of diamond outweigh? A typical engagement ring setting uses about 3 pennyweights (4.7 grams) of gold. One carat of diamond weighs 0.1286 pennyweights. So the gold in the setting outweighs the diamond by roughly 23 to 1. 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