Calculating the witness size of a transaction

[Bitcoin]

Calculating the witness size of a transaction

I want to calculate how many % of a block, and thus, transactions that are witness data. I need to calculate the size of the witness data in bytes in every transaction. And as I understand it, I cannot calculate this using existing size variables like vsize.

Will a loop through the "txinwitness" array of hex and do a byte length calculation on every one be enough? (Using NodeJS here)

Buffer.byteLength('03fbcc1c24903bc2fb1d73czef518b859232341c39e4515367653d80536d587b62d6', 'hex');

Source: Calculating the witness size of a transaction