Using the formula provided by the wiki we have created as simple of a calculator we could.
Enter the item name, amount, purchase price and resale price.
Fee's described as "Fee" is regular tax rate. "Discount Fee" is with lvl3 intel. applying the 30% discount.
Actual fee may vary by <1200 at very high prices but other wise, it's as accurate as we can get I believe.
EDIT: In my personal opinion(not based off hard facts) Fee calculation is different per item, IF the purchasing values are different. Therefore the exponential function gives out slightly different answers per value given to it. Hence the slight inaccuracy. Does anyone think differently or have any other reasoning? Am interested.
RE-EDIT: To those asking, make a copy from the "file" dropdown for your own personal use one, as this is view only.
Source: https://www.reddit.com/r/EscapefromTarkov/comments/f0wmvp/find_out_your_market_tax_b4_you_buy/
