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PARAMETERS & EXPRESSIONS
Look up the operators, functions and if-statements that Autodesk Fusion uses in parameters and expressions, then line them up against SOLIDWORKS, Onshape, Inventor, Creo, NX, CATIA, Solid Edge, FreeCAD, Shapr3D, AutoCAD and PowerMill. Every app links to its publisher’s own help pages.
13 CAD/CAM apps / Fusion first
Find the right syntax.
Pick your software to see how it writes parameters and formulas. Every other app lines up beside Fusion, so you can translate a formula either way.
Autodesk Fusion
Parameters · Design workspace
- Where
- Modify › Change Parameters. Or type
Width = 50 mmin any dimension box to make a named parameter on the spot (named parameters go straight into Favorites). - Write it like
- Name
Length, ExpressionWidth * 2 - Arguments
;— never a comma- Angles
- Give them a unit:
sin(30 deg),sin(PI / 4 rad) - If
if(test; a; b)
In our glossary: User parameter · Model parameter · Expression · Parametric modelling
Syntax at a glance
| What you want | Fusion |
|---|---|
| Basics | |
| Use a parameter | WidthModel parameters get names like d12. Rename the ones you reuse. |
| Type a value with units | 50 mm15 deg |
| Separate function arguments | ;Autodesk avoids the comma because many countries use it as the decimal mark. |
| Arithmetic | |
| Power | a ^ bpow(a; b)pow rounds decimal powers at the 8th decimal place. |
| Remainder (modulo) | a % bFloating-point remainder. |
| Square root | sqrt(x) |
| Absolute value | abs(x) |
| Smaller or larger of two | min(a; b)max(a; b) |
| Sign of a number | sign(x)Autodesk’s table says 0 for negative and 1 for positive values. Test it before you rely on it. |
| Random number | random() |
| Rounding | |
| Round to nearest | round(x)Needs a unitless value. Halves round away from zero: round(-1.5) = -2. |
| Round up | ceil(x)Unitless: ceil(-1.5) = -1. |
| Round down | floor(x)Unitless: floor(-1.5) = -2. |
| Drop the decimals | Not in the docsNo trunc. For a unitless x: if(x < 0; ceil(x); floor(x)). |
| Trig and angles | |
| Angle units in trig | sin(30 deg)sin(PI / 4 rad)Trig takes an angle with a unit and returns a plain number. |
| Sine, cosine, tangent | sin(x)cos(x)tan(x)Also sinh, cosh, tanh. |
| Inverse trig | asin(x)acos(x)atan(x)They return an angle. Also asinh, acosh, atanh. |
| Two-argument arctangent | Not in the docs |
| Powers and logs | |
| Natural log (base e) | ln(x) |
| Log base 10 | log(x)Autodesk doesn’t state the base. Quick check: if log(100) shows 2, it’s base 10. |
| e to the power of x | exp(x) |
| Constants | |
| Pi | PI |
| Euler’s number e | E |
| Logic | |
| If / else | if(test; a; b)Put another if inside for more than two outcomes. |
| Equal to (comparison) | == |
| Not equal to | <>Not !=. |
| And, or, not | (a) and (b)(a) or (b)notExample: if((Height < 400 mm) and (Width < 400 mm); 12 mm; 18 mm) |
More in Fusion
Gravity- Standard gravity, 980.665 cm/s².
SpeedOfLight- 29,979,245,800 cm/s.
cosh(x) · sinh(x) · tanh(x)- Hyperbolic functions. They take an angle.
acosh(x) · asinh(x) · atanh(x)- Inverse hyperbolic functions.
Part number {PartNumber}- A text parameter. Type the text in the Expression box; wrap a parameter name or expression in curly braces to insert its value.
_ " $ ° µ- Symbols you can use in parameter names, besides letters and numbers.
Watch out
- Use
;between arguments:max(a; b), notmax(a, b). - Not equal is
<>. round,floorandceilneed a unitless value. Divide by a unit, then multiply back:floor(Length / 5 mm) * 5 mmrounds down to the nearest 5 mm.- Don’t name a parameter after a unit such as
mm,inordeg. - Change Parameters exports your user parameters to a CSV file and imports them into other designs. Autodesk advises giving every parameter a unique name to avoid conflicts on import.
- Editing lots of parameters? Untick Automatic Compute in the Parameters dialog; the design then updates when you click OK.
Sources
Checked 9 Nov 2026. If a publisher’s page doesn’t cover something, the table says so instead of guessing. Try new formulas on a scratch file first.
Product names belong to their owners. Syntax can change between releases, so check the linked help pages for your version.