Doing math operation inside INVOICE TERMS

I would like to add Dynamic Terms and Policies in my invoices using Custom Fields. Is this possible?

For example, I would lo to add as default on my TERMS something like:

Please remember is you plan to pay in USD the correct amount will be: ($subtotal * $exchange_rate)

Is this possible?


@david can this be accomplished with TWIG?

TWIG is inside the template builder?

Never use TWIG, so not sure about this.

It may be possible to use TWIG in a custom design to accomplish this.