Expressions in Variables

The ability to make variables that are aliases of other variables is useful, but it would also be incredibly valuable to make variables that are defined via an expression relating them to other variables.

For instance much of the sizing in our design system is done in REMs, being able to create a variable in the sheet where REM=16 and then another variable BORDER RADIUS= 0.25*REM would be very powerful


Or create derived values for prototyping purposes, like price totals on a cart page. Right now, you have to manually sum them and assign them to a variable with an interaction, which is awesome! but not ideal.

Absolutely needed. Designing fully a scalable UI isn’t really possible so developers need to come up with their own ratios. This has lead to many implementations that aren’t exactly according to spec.
If you could just say that, e.g., an element width is 40% of the frame width, which can now thankfully be from a variable, you can just design the spec into the plan directly.

Duplicate of Using expression as a variable's value ?
Let’s centralize the upvotes?

I agree it is definitely a need for REM or many other simple use cases like ratios. +1