Objects in mid-air.

Well, some of us just can't aford to buy a hexadecimal calculator.
But wait, we can use windows' calculator!
OMG!!!!!!!!

Using Google Calculator requires less steps of you.

Just use as a search query: <THINGHEIGHT> * 16 + 7 in hex.

For example, "64 * 16 + 7 in hex",
http://www.google.com/search?hl=en&q=64*16+7+in+hex&btnG=Google+Search
Gives "0x407" as the answer. Add a fourth digit there (to be 0x0407) and you've got yourself a correct hex value for Wadauthor to use.

Or you can just use Doom Builder. Whatever.