# Catching Errors Through Mathcad Units

Unit conversion is one of Mathcad’s most useful features. Mathcad provides the ability to track and balance units, helping you avoid costly and even dangerous mistakes. You can easily convert between multiple unit systems by just typing in a unit from another system as shown below:

Simple conversions

Mathcad’s default unit system is SI (International System of Units). Because Mathcad balances units, you can use Mathcad for dimensional analysis, and catch errors in your work. Mathcad double-checks to make sure you type in an equation correctly, use a correct formula, and insert the correct units.

A crane picks up a 25 kg beam off the ground and puts it on 36 foot wall. How much work did the crane do?

Uses of rapid conversion

Mathcad also combines units into simpler units for you, unless you turn it off. Look at the result above, when simplify units are turned off.

Suppose instead of energy you asked for the result in units of force.

Mathcad shows your error by balancing the units and giving you an extra m for meters. To correct the error, you try force per length, which still has leftover units.

Finally you put in a different unit of energy and the equation has no leftover units.

Customizing Units

Mathcad has many units, but you can easily define custom units, if you need to.

One unit that Mathcad doesn’t include is barrels of oil. In the United States bbl stands for one barrel of 42 US gallons of oil.

Units can be created, too.

The volume of 5 barrels of oil is 795 liters.

In the upcoming release of Mathcad Prime 1.0, you’ll see how we’ve expanded units throughout Mathcad, adding them to almost all functions, and adding mixed units to matrices, vectors, solve blocks, and plots. We’re also returning to dynamic units, at the request of many users.

Take advantage of all Mathcad has to offer in the way of units, always using them to check your calculations.

Mona Zeftel Mathcad, Senior Technical Consultant