The following are the commonly used formulas that we have been using for several years. Here we include the basic functions that allow us to develop simple and complex formulas.
Basic operations
Functions
The following characters tell Revit what to do between 2 values.
Command in Revit
+
–
*
/
=
<
>
^
Sum
Sum
Subtract
Multiplication
Division
Equal
Less than
More than
Exponentiation
Declarations
The following statements tell Revit whether the formula will be a Boolean, alternative, or rounding. These are included at the beginning of the formula.
Command in Revit
IF()
AND()
OR()
NOT()
ROUND()
ROUNDDOWN()
ROUNDUP()
LOG()
Definition
Conditional declaration
Declaration to add
Declaration to have an alternative
Opposite / flase declaration
Rounding
Rounding down
Rounding up
Logarithm
Formulae
The following formulas outline the basic operations that can be used in Revit.
Conditional formula
A formula that gives a numerical value based on the condition being true.
Formula
IF ([Conditional], [Value if true] , [Value if false])Example
X = IF ( A > B , Z , Y )
Conditional formula with text
A formula that gives a text value based on whether the condition is true or false.
Note: The text value as a result must be enclosed in quotation marks.
Formula
IF ([Conditional], [Value if true] , [Value if false])Example
X = IF ( A > B , “True” , “False” )
Nested conditional formula IF() and AND()
A formula that gives a result based on two conditionals.
Formula
IF( AND( [Conditional 1], [Conditional 2]) , [Value if true] , [Value if false])Example
X = IF ( AND( A > B, A > C) , “True” , “False” )
Nested conditional formula IF() and OR()
A formula that gives a result based on one of two conditions being true.
Formula
IF( AND( [Conditional Alternative 1], [Conditional Alternative 2]) , [Value if any alternative is true] , [Value if no alternatives are true])Example
X = IF ( OR( A > B, A > C) , “True” , “False” )
Exponential
Formula that returns the exponential of a value to the indicated power.
Formula
[Numeric Value] ^ [Exponential]Example
X = Y ^ E
Exponential of E
Formula that returns the exponential E of a value.
Formula
exp([Numeric Value])Example
X = exp(N)
Circles
Formula to calculate the value of the circumference and/or area of a circle.
Formula
Circumference = pi() * ([Radio] * 2)
Area = pi() * [Radio] ^ 2Example
(Circumference) X = pi() * (Radius * 2)
(Area) X = pi() * Radius ^ 2
Square Root
Formula to calculate the square root of a numerical value.
Formula
sqrt([Numeric Value])Example
X = sqrt(N)
Force (Yes/No) parameters to Yes
Formula that blocks a parameter to check (Yes)
Formula
[1 < 2] , [1 = 1]Example
X = 1 < 2 , X = 1 = 1
Force (Yes/No) parameters to No
Formula that blocks a parameter to uncheck (No)
Formula
[1 > 2] , [1 = 0]Example
X = 1 > 2 , X = 1 = 0
Trigonometry with Right Triangles
The following formulas help us to calculate the values of angles and lengths of a triangle knowing 2 values of the triangle.
Known: a + b
Formula
c = sqrt(a ^ 2 + b ^ 2)A = atan(a / b)
B = atan(b / a)
Known: a + c
Formula
b = sqrt(c ^ 2 - a ^ 2)A = asin(a / c)
B = acos(a / c)
Known: b + c
Formula
A = acos(b / c)
a = sqrt(c ^ 2 - b ^ 2)B = asin(b / c)
Known: c + A
Formula
a = c * sin(A)b = c * cos(A)
B = 90° – A
Known: c + B
Formula
a = c * cos(B)b = c * sin(B)
A = 90° – B
Known: a + B
Formula
b = a * tan(B)c = a / cos(B)
A = 90° – B
Known: b + A
Formula
a = b * tan(A)c = b / cos(A)
B = 90° – A
Known: a + A
Formula
b = a / tan(A)c = a / sin(A)
B = 90° – A
Known: b + B
Formula
a = b / tan(B)c = b / sin(B)
A = 90° – B
We hope you find this list useful.
If there is a formula you need, please describe it in the comments…
