“KT” (or “kt”) is an abbreviation with several widely used meanings depending on the context. It most commonly refers to a karat (a measure of gold purity), a knot (a unit of speed), or knowledge transfer (a business process). Less frequently, it points to the K-T boundary in geology or KT Corporation in South Korea. Here’s what each one means and when you’ll encounter it.
Karat: Gold Purity
In jewelry, “kt” (also written as “K” or “k”) stands for karat, a unit that measures the purity of gold out of 24 parts. Pure gold is 24 karats, meaning all 24 parts are gold with no other metals mixed in. Any number below 24 tells you the piece is an alloy, a blend of gold with metals like silver, copper, or zinc added for strength and durability.
The most common karat levels you’ll see stamped on rings, necklaces, and bracelets are:
- 10K: 41.7% gold. The minimum karat that can legally be sold as gold jewelry in the United States. It’s the most affordable and most durable option because the higher alloy content resists scratching.
- 14K: 58.3% gold. The most popular choice for everyday jewelry in the U.S., balancing price, durability, and a rich gold color.
- 18K: 75% gold. Noticeably warmer and more yellow than 14K, but softer and more prone to scratches. Common in fine jewelry and luxury brands.
- 24K: 99.9% gold. Too soft for most jewelry but used in gold bars, coins, and some traditional pieces in parts of Asia.
If you’re shopping for gold jewelry, the karat stamp is usually found on the inside of a ring band or on the clasp of a chain. A higher karat number means more gold content, a richer color, and a higher price, but also a softer piece that’s more vulnerable to daily wear.
Knot: A Unit of Speed
In aviation, sailing, and meteorology, “kt” is the standard abbreviation for knot. One knot equals one nautical mile per hour, which works out to about 1.15 standard (statute) miles per hour or roughly 1.85 kilometers per hour. The National Weather Service and aviation authorities worldwide use knots as the default unit for reporting wind speeds and aircraft velocity.
The knot exists because nautical miles are based on the geometry of the Earth. One nautical mile equals the length of one minute of latitude, which makes navigation calculations simpler when plotting courses on charts. If a weather report says winds are 25 kt, that translates to about 29 mph or 46 km/h. Pilots, sailors, and meteorologists all speak in knots, so understanding this abbreviation helps you read marine forecasts, aviation weather briefings, and storm reports.
Knowledge Transfer in Business
In corporate and IT settings, “KT” stands for knowledge transfer. It’s the process of moving expertise, procedures, and institutional know-how from one person or team to another. This happens during employee onboarding, project handoffs, mergers, software implementations, and when experienced employees retire or leave the organization.
Knowledge transfer goes beyond simply handing someone a document. It involves converting the knowledge inside people’s heads into content, learning materials, tools, and processes that others can use. A typical KT effort starts by identifying what critical knowledge exists and where the gaps are, then designing a structured plan to capture and share that information through documentation, training sessions, shadowing, or mentoring.
If you hear “KT session” or “KT period” at work, it usually means a scheduled block of time where an outgoing team member walks an incoming person through responsibilities, systems, contacts, and unwritten rules that aren’t in any manual.
The K-T Boundary in Geology
In earth science, the K-T boundary (also called the K-Pg boundary) marks the dividing line between the Cretaceous and Tertiary periods, roughly 66 million years ago. The “K” comes from the German word for Cretaceous (Kreide), and the “T” from Tertiary. This boundary corresponds to one of the most catastrophic mass extinctions in Earth’s history, when at least 75% of all species were wiped out, including the non-avian dinosaurs.
The extinction is linked to a massive asteroid impact at what is now the Chicxulub crater in Mexico’s Yucatán Peninsula. In the oceans, more than 90% of plankton were extinguished, collapsing the marine food chain. Geologists can identify the K-T boundary at sites around the world as a thin clay layer separating older rock containing dinosaur-era fossils from younger rock dominated by mammal fossils. Some scientists now prefer the name “K-Pg boundary” (Cretaceous-Paleogene), but K-T remains widely recognized.
KT Corporation
In the business world, KT can also refer to KT Corp, a major South Korean telecommunications company headquartered in Seongnam. Originally known as Korea Telecom, KT provides wireless and wired phone service, high-speed internet, IPTV, satellite broadcasting, and a range of enterprise IT services. It’s one of South Korea’s largest telecom providers and trades on major stock exchanges under the ticker symbol KT.