WOLFRAM

Wolfram Language & System Documentation Center
Do Calculations with Units

Do Calculations with Units

Units are automatically converted during arithmetic operations.

    
Use Quantity to represent units:
Wolfram Language code: Quantity[19.25, "Kilometers"] + Quantity[13, "Miles"]
Wolfram Language code: Quantity[20, "Feet"] / Quantity[2.3, "Seconds"] + Quantity[9, "Meters" / "Seconds"]
Arithmetic operations also handle unit cancellation automatically:
Wolfram Language code: N[Quantity[175, "Pounds"] / Quantity[100, "Kilograms"]]
Estimate the number of miles that can be traveled on a low tank of gas. IndependentUnit is used to represent an arbitrary unit with no relationship to other units within Quantity:
Wolfram Language code: Quantity[24, "Miles" / "Gallons"] * Quantity[16.2, "Gallons" / IndependentUnit["tank"]] * Quantity[1 / 8, IndependentUnit["tank"]]