GNU Units MCP server

This is a small helper that lets your AI convert measurements between units, like miles to kilometres or pounds to kilograms. It uses the same unit data as GNU units, a well known free conversion program, and it works without an internet connection. It is handy for anyone who deals with numbers and units, like engineers, students, analysts, or anyone who keeps second-guessing their conversions.

What this MCP server does

You ask your AI something like how many litres are in 3 gallons. Your AI passes the question to this helper. The helper looks up the units in the GNU units database and does the maths carefully, keeping track of what kind of quantity it is. Then your AI tells you the answer in plain words, with the exact number. It can also handle combined units like kilowatt hours or acre feet, and it can break any unit down into its basic SI parts.

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What you can do with it

• Convert a value from one unit to another, like 12 inches to centimetres
• Work out compound units such as kilowatt hours or acre feet
• Reduce any unit to its basic SI base units
• Search the unit database by keyword to find the right unit name
• Look up the exact definition of a unit, prefix, or physical constant
• List the prefixes like kilo, milli, and mega that units can use

Try asking your AI

• “How many litres is 3.5 gallons?”
• “Convert 90 miles per hour to metres per second”
• “What is 5 kilowatt hours in joules?”
• “Reduce an acre foot to SI base units”

What it gives back to you

You get a clear answer in the chat, usually a number with its unit, like 13.24 litres or 40.23 metres per second. When you search for units, you get a list of matching names. When you ask for a definition, you get the exact wording from the GNU units database. Everything comes back as text you can read right away.

Before you start

Who it's for

Engineers, scientists, students, and anyone who works with measurements and wants quick, reliable unit conversions.