Custom Calculated Fields

Hello,

Is it possible to create a general calculated field in Manager.io that performs automatic calculations within accounting transactions?

For example:
If the real estate transaction tax due is 70,000 SAR, and the exemption for the citizen is 50,000 SAR, the calculated field should automatically show the final tax as 20,000 SAR after applying the exemption.
(Original tax: 70,000 SAR – Exemption: 50,000 SAR = Final tax: 20,000 SAR)

I am interested in similar automated calculations for other accounting scenarios as well.

Thank you.