Numeric Fields
Numeric measurements are required in multiple fields in Part Studio and Assembly.
When entering values and parameter expressions in numeric fields throughout Onshape, you can use the keyboard and also the mouse scroll wheel:
Scroll+Key  Result 

scroll wheel default  increments of 0.1 
Ctrl+scroll wheel  increments of 0.01 
Shift+scroll wheel  increments of 1.0 
Numeric value fields throughout Onshape Part Studios and Assemblies accept integers, decimals (comma separators also accepted), parameter expressions, and trigonometric functions. Default units dictate the unit when no other unit is entered in the numeric field, but you can always enter any unit. Onshape will convert and display the value in default units. When you click in the field, however, the original units are displayed again.
Keyword type  Keywords accepted  Examples 

Length 
mm, millimeter, cm, centimeter, m, meter, in, inch, ft, foot, yd, yard 
5mm

Angle units 
deg, degree, rad, radian 
7deg (or 7 degree)
14rad (or 14 radian) 
Math functions 
+, , *, /, ^, ceil, floor, round, exp, sqrt, abs, max, min, log, log10 
2^3

Modulo operator 
% 
5%2 (returns 1) 
Trigonometric functions 
cos, sin, tan, acos, asin, atan, atan2, cosh, sinh, tanh, asinh, acosh, atanh 
These functions are in degrees, not radians. For example: sin(30) = sin(30 deg) = .5
atan2(4, 5) (Give the polar angle of (5,4) in as an angle) 
Constants 
pi, PI, Pi 
(3*pi) in 
Parameter expressions are evaluated as FeatureScript.
 Parameter expressions are available in Part Studios and Assemblies.
 Parameter expressions must either result in a unitless value, or result in a unit value to the first power.
 After a numeric field has been accepted, the evaluation of the expression is displayed. When the field is active again, the original expression is displayed.
 Use any units (if the field accepts units), but don't mix types (such as degrees and millimeters):
Valid
Invalid
3in+2.5in
3+2.5in
3mm+2.5in
3mm+2deg
3+2
3in+2 (2*3)*(1/3)
(2*3)(1/3)
sqrt(16)m
sqrt(16m)
cos(30deg)
30 ^{o}
 Plurals of all length and angle units are allowed (for example: feet, radians, etc.).
 Most parameters are lengths or angles. Some parameters are unitless, like Rho and pattern instance counts.
 Fractions are supported.
 Use parentheses when necessary. For example, (2*3)*(1/3).
 See Variable Studios for information on creating global variables.
For unitless expressions, all unitless expressions are accepted and follow the standard order of evaluation. For example: 3+(2*3)/6
For singleunit expressions, all single units are accepted if the expression ends with a unit to the first power. For example: 3mm+(2mm*3mm)/(6mm), and 3mm+2mm
For multipleunit expressions, all multipleunit expressions are accepted if the result is a unit to the first power. For example: 3[unit]+3[unit] is accepted, but 3[unit]*3[unit] is not accepted.
When creating custom features using FeatureScript, you are able to use trigonometric functions in numeric fields. Keep the following in mind:
Unitless parameters are accepted. For example: sin(30) and sin(asin(1)).
Inverse trigonometric functions are accepted. For example: atan(1), atan(1)/deg. Be aware that asin/acos/atan return a degree, so you need to divide by degree to get a unitless value.
For more information on FeatureScript, see Welcome to FeatureScript and for more information on creating custom features, see Add Custom Features.
Onshape supports array/lookup tables such as this:
[3,5,6,7][2] with:
 [3,5,6,7] being the array
 [2] being the position
 6 being the second value in the array
Remember the array starts at position 0.
Another example is: [3,5,6,7][3]=7
When commas are used as decimal separators, a space must be added between array values in an expression (for example: [1, 4, 9, 16][#i], and not [1,4,9,16][#i]). See Decimal format.
You can also use ternary operators (such as '?') which may yield conditional results. For example, say the length of a sketch entity should be 7 inches if the width is greater than 5 inches. It can be written this way:
#width>5?7:4
Where:
 #width>5 is the conditional statement
 ? is the ternary operator
 7 being if the expression is true (if the width is greater than 5), make the length 7 inches
 4 being if the expression is false (if the width is 5 or less), make the length 4 inches
You can use logic operators, such as:

&& for 'and'

 for 'or'
For example:
(#width > 3in && #width < 5in) ? 3 : 2
This returns 3 if the value satisfies both conditions, and otherwise returns 2.
(#width > 3in  #alwaysReinforce) ? 3 : 2
Where #alwaysReinforce is a configuration checkbox, and returns 3 if the value satisfies either condition, and otherwise returns 2.
 3in*3in
 3+3in (Because unitless+unit does not compute.)
 3[unit]*3[unit] (This results in [unit]^2, which is not accepted.)
 sin(30)/deg (This results in a 1/deg unit, which is not accepted.)
 Anything resulting in 1/[unit] is not accepted.
 A unit over a unit if there is a separate unit, for example: 3[unit]+1[unit]/2[unit].
 Inverse trigonometric functions take numeric values and return angles; for example: atan(1) = 45 degrees.
 To use a unitless value (perhaps to enter into a dimension field), divide by the default angle unit; for example: [atan(1)/deg].
 Plurals of all length and angle units are allowed (for example: feet, radians, etc.).
 Use parentheses when necessary. For example, (2*3)*(1/3).
 Fractions are supported.
 Commas can be used as decimal separators in numeric value fields.
 For information on how to apply the settings for commas as decimal separators, see the Decimal format section in Setting Preferences.
 Most parameters are lengths or angles. Some parameters are unitless, like Rho and pattern instance counts.
 See Variable Studios for information on creating global variables.
Numeric value fields throughout Onshape Part Studios accept integers, decimals, expressions and trigonometric functions. Default units dictate the unit when no other unit is entered in the numeric field, but you can always enter any unit. Onshape converts and displays the value in default units. When you tap in the field, however, the original units are displayed again.
Expressions are entered into numeric fields using the Mobile Number Pad's keyboard option (see Numeric Fields). Currently, expressions can be used only in Part Studios.
Keyword type  Keywords accepted  Examples 

Length 
mm, millimeter, cm, centimeter, m, meter, in, inch, ft, foot, yd, yard 
5mm

Angle units 
deg, degree, rad, radian 
7deg (or 7 degree)
14rad (or 14 radian) 
Math functions 
+, , *, /, ^, ceil, floor, round, exp, sqrt, abs, max, min, log, log10 
2^3
abs(4) max(2, 3) (sqrt(2in * 3mm)) and sqrt(4 in^2) exp(2) 
Modulo operator 
% 
5%2 (returns 1) 
Trigonometric functions 
cos, sin, tan, acos, asin, atan, atan2, cosh, sinh, tanh, asinh, acosh, atanh 
These functions are in degrees, not radians. For example: sin(30) = sin(30 deg) = .5
atan2(4, 5) (Give the polar angle of (5,4) in as an angle) 
Constants 
pi, PI, Pi 
(3*pi) in 
Onshape supports array/lookup tables such as this:
[3,5,6,7][2]=6 with:
 [3,5,6,7] being the array
 [2] being the position within the array
 6 being the value
Remember the array starts at position 0.
Another example is: [3,5,6,7][3]=7
You can also use ternary operators (such as '?') which can yield conditional results. For example, say the length of a sketch entity should be 7 inches if the width is greater than 5 inches. It can be written this way:
#width>5?7:4
Where:
 #width>5 is the conditional statement
 ? is the ternary operator
 7 being if the expression is true (if the width is greater than 5), make the length 7 inches
 4 being if the expression is false (if the width is 5 or less), make the length 4 inches
 With the number pad open, tap the keyboard button.
The number pad minimizes and a keyboard appears.
 Enter an expression with the keyboard.
 Tap the check to accept the expression or the x to cancel.
 Expressions are available in Part Studios and Assemblies.
 Expressions must either result in a unitless value, or result in a unit value to the 1st power.
 After a numeric field has been accepted, the evaluation of the expression is displayed. When the field is active again, the original expression is displayed.
 Use any units (if the field accepts units), but don't mix types (such as degrees and millimeters):
Valid
Invalid
3in+2.5in
3+2.5in
3mm+2.5in
3mm+2deg
3+2
(2*3)(1/3)
(2*3)*(1/3)
sqrt(16m)
sqrt(16)m
30 ^{o}
cos(30deg)
 Plurals of all length and angle units are allowed (for example: feet, radians, etc.).
 Most parameters are lengths or angles. Some parameters are unitless, like Rho and pattern instance counts.
 Fractions are supported.
 Use parentheses when necessary. For example, (2*3)*(1/3).
 See Variable Studios for information on creating global variables.
For unitless expressions, all unitless expressions are accepted and follow the standard order of evaluation. For example: 3+(2*3)/6
For singleunit expressions, all single units are accepted if the expression ends with a unit to the first degree. For example: 3mm+(2mm*3mm)/(6mm), and 3mm+2mm
For multipleunit expressions, all multipleunit expressions are accepted if the result is a unit to the first degree. For example: 3[unit]+3[unit] is accepted, but 3[unit]*3[unit] is not accepted.
You can use trigonometric functions in numeric fields. Keep the following in mind:
Unitless parameters are accepted. For example: sin(30) and sin(asin(1)).
Inverse trigonometric functions are accepted. For example: atan(1), atan(1)/deg. Be aware that asin/acos/atan return a degree, so you need to divide by degree to get a unitless value.
 3in*3in
 3+3in (Because unitless + unit does not compute.)
 3[unit]*3[unit] (This results in [unit]^2, which is not accepted.)
 sin(30)/deg (This results in a 1/deg unit, which is not accepted.)
 Anything resulting in 1/[unit] is not accepted.
 A unit over a unit if there is a separate unit, for example: 3[unit]+1[unit]/2[unit].
 Inverse trigonometric functions take numeric values and return angles; for example: atan(1) = 45 degrees.
 To use a unitless value (perhaps to enter into a dimension field), divide by the default angle unit; for example: [atan(1)/deg].
 Plurals of all length and angle units are allowed (for example: feet, radians, etc.).
 Use parentheses when necessary. For example, (2*3)*(1/3).
 Fractions are supported.
 Most parameters are lengths or angles. Some parameters are unitless, like Rho and pattern instance counts.
 See Variable Studios for information on creating global variables.