Here is why I was wanting to know.
I've read some pages of people making slants/plates by simply measuring out the DME & Agar dry into each slant/plate, then adding hot water with a dosing syringe.
This seems less wasteful than my current method of making up 100ml of wort/agar, pouring too many plates, and then having them dry up before I can use them.
I wanted the conversion so I could make this spreadsheet. I can enter the numbers in column B, it will tell me what I need in column F.