Software for unit aware calculations?

Question

When doing engineering calculations it is great convenience to do have software that keeps track of units.

Example when calculate something trivial as stress:

$\sigma = \frac FA$

And be able to write:

$\frac {1kN}{1m*1mm}$ and get the answer in MPa

This is by nature a poll thread that i know is frowned upon on StackOverflow, is it going to be closed?

Answer 1

Google Calculator does this nicely for units it knows about:

And you can't beat the price.

Answer 2

I'll add F# to the list.

Floating point and signed integer values in F# can have associated units of measure, which are typically used to indicate length, volume, mass, and so on. By using quantities with units, you enable the compiler to verify that arithmetic relationships have the correct units, which helps prevent programming errors.

Answer 3

MathCad handles units in a nice way but it is too expensive for home use.

Answer 4

One of the top search results for "units software" is the appropriately named GNU Units, which lets you say

You have: ten furlongs per fortnight
You want: kilometers per hour

and tells you "0.0059871429".

Answer 5

There is SpeQ Mathematics for Windows environments. It is probably more of what your looking for.

http://www.speqmath.com/index.php?id=1

Answer 6

You might be interested in Frink.

It has an interpreter that you can download as a desktop app. It also has a web interface, which lets you type

in  >> 1 kN / (1 m * 1 mm)
out >> MPa

to get

result >> 1 MPa

There is a list of sample calculations covering a wide variety of physical applications.