Calculation formula within variable input

This really is a key feature to enable scalable design systems. Would be super grateful if this could be added.

When creating variables, it would be really useful to be able to include maths and text when defining a variable, which are kept up-to-date based on current values.

E.g.
With a shopping basket, I have the following variable
• Subtotal# (numeric)
Into which I add the value of each product selected in the basket.

From this value I would like to calculate
• VAT# (numeric) = Subtotal * 20%, truncated to 2 decimal places

And then display these variables in a currency
• Subtotal£ (String) = “£” + Subtotal#
• VAT£ (String) = “£” + VAT#
• Total£ (# String) = “£” + Subtotal#+VAT#

This way, I could just add/remove the product costs from Subtotal#, and use the strings for display in the prototype.

Hi @Dave_Curtis, my new plugin does exactly what you want, give it a try!
https://www.figma.com/community/plugin/1365339609215368041/dynamic-variables

Here’s the list of your expressions, but with the syntax of my plugin,
just paste these {{ }} expressions into the description fields of the corresponding variables and run the plugin Dynamic Variables → Start Monitoring Changes or Dynamic Variables → Update Once:

• VAT# (numeric) = {{ $Subtotal * .2 }}
• Subtotal£ (String) = {{ "£" + ( $Subtotal ).toFixed(2) }}
• VAT£ (String) = {{ "£" + ( $VAT ).toFixed(2) }}
• Total£ (# String) = {{ "£" + ( $Subtotal + $VAT ).toFixed(2) }}

Hope this helps!

Thanks @neelts - this looks really promising.

Please Figma team, add this feature

Basically Excel/Sheets like input possibilities, that would make prototypes more lively and real.

I’d love to see a number to HEX converter (text) “HEX(red-value)” (or something like that) and the possibility to use a text variable as colour. That would be possible if variables would allow formulas as value.

+1

+1 for this for sure…

+1 for this