Deka has several meanings depending on context. Most commonly, it refers to a metric prefix meaning 10, used in measurements like dekameter (10 meters) or dekagram (10 grams). It also appears as the name of a well-known engineering company and a medical laser manufacturer. Here’s what each one means and where you’re likely to encounter them.
Deka as a Metric Prefix
In the metric system, deka (symbol: da) is the prefix that multiplies a unit by 10. A dekameter is 10 meters, a dekaliter is 10 liters, and a dekagram is 10 grams. The prefix comes from the Ancient Greek word déka, meaning “ten,” and has been part of the metric system since its creation in 1795.
You’ll sometimes see it spelled “deca” instead of “deka.” The difference is regional: the National Institute of Standards and Technology (NIST) uses “deka” as the official American English spelling, while “deca” is the British English version. Both refer to the same thing. The international scientific authority on units, the Bureau International des Poids et Mesures (BIPM), lists the prefix as “deca” with the symbol “da.”
One quirk worth noting: most metric prefixes for larger quantities use uppercase symbols (like M for mega or G for giga), but deka is one of three exceptions that stays lowercase. Kilo (k) and hecto (h) are the other two.
In everyday life, you’ll run into this prefix most often with the decathlon (ten athletic events) or in cooking and nutrition, where dekagrams occasionally appear on European food labels. It’s far less common than kilo or centi, but it shows up enough that knowing it means “ten” covers most situations.
DEKA Research and Development
DEKA is also a technology and engineering company founded in 1982 by inventor Dean Kamen, best known as the creator of the Segway. Based in Manchester, New Hampshire, the company focuses primarily on medical devices and mobility technology. Kamen started it after selling his first company, AutoSyringe, at age 30, with the goal of building medical innovations that improve daily life.
The company’s portfolio spans several fields: robotics, personal mobility, water purification, and dialysis systems. Its most notable products include the Segway Human Transporter, the iBOT (a powered wheelchair that can climb stairs and raise its user to standing height), and the DEKA Arm System, a highly advanced prosthetic.
The DEKA Arm System
The DEKA Arm, often called the “Luke Arm” (a nod to Luke Skywalker), is a prosthetic designed for adults who have lost part or all of an upper limb, or who were born without one. The FDA cleared it in 2012, and it remains one of the most capable prosthetic arms available.
What makes it stand out is its range of movement. The arm provides up to 10 independent points of motion, covering the shoulder, elbow, wrist, and individual fingers, including the thumb. That level of control lets users perform tasks that simpler prosthetics can’t handle well, like picking up a key, gripping a cup, or carrying a 20-pound bag of groceries. It’s also built to handle a full gallon of milk. For safety, the hand includes a grip release button (with a backup) that disengages all the joints in the shoulder, elbow, and arm within five seconds, letting someone manually reposition the limb in an emergency.
DEKA Medical Lasers
Completely separate from DEKA Research, DEKA M.E.L.A. is an Italian manufacturer of medical and aesthetic laser systems used in dermatology clinics and medical spas. If you’ve come across the name “DEKA” in the context of skin treatments, hair removal, or cosmetic procedures, this is likely what was being referenced.
Their systems combine multiple light sources in a single device. One FDA-cleared platform, for example, pairs two different laser wavelengths with intense pulsed light to treat a range of skin concerns: unwanted hair, pigmented spots, wrinkles, and visible blood vessels. These are professional-grade systems used by dermatologists and trained clinicians, not consumer products.