Some sizing rules in a formula in Autodesk Revit

Formulas can work on the following types of data:

• Number with units
• Boolean values ​​(yes / no)
• Strings (text)

In relation to the units:

• For the additions, the entries and the result must have the same type of numerical unit.
• Multiplication supports all types of numeric units for inputs (not necessarily the same type). However, the result must be the product of the units entered. For example: length * area = volume.
• sin () requires entering an angle value, and the output must be a number without a unit type.
• if () requires a first boolean argument. The other arguments and the result can be of any data type (numeric, boolean, text), but they must all be of the same data type.

Revit uses the basic physical dimensions (Time, Length, Mass, Temperature, etc.). Dimensional analysis is independent of the unit used to represent or measure the basic physical dimension (seconds, meters, kg, degrees Celsius, etc.).

With respect to the constants:

If we do not put the unit to a number, Revit interprets it to agree with the units of the formula. This is why several people add * 1 or / 1 to a formula. However, it is recommended that you specify the units for each constant in the formula. Here are some of the most used units.