Taking a leak at the Kentucky Derby could cost you $18,000 ... because that's what several companies paid per person to reserve a spot on the corporate pavillion -- and TMZ has pics of their VIP crappers.
Here's how the math breaks down -- according to a sales rep for the Derby, 7 companies paid $450,000 each for a spot in the swanky Trackside Village on Turn One ... where toilet experts posted up 2 VIP restroom trailers. That's $3.15 million total for all the companies.
Trackside Village's capacity is capped at 175 people -- and $3,150,000 divided by 175 equals $18,000 a person.
Sure, that figure also includes catering and drinks ... but let's not kid ourselves ... the toilets are obviously the main attraction.