Haha, I have this paper! And you didn’t add a photo it btw
The 30 in. are converted to 2.5 feet.
The sides:
(30 x 2.5) ÷ 2 = 37.5
37.5 + 37.5 = 75
Back:
2.5 x 6 = 15
Top:
30.1 x 6 = 180.6
180.6 + 75 + 15 = 270.6
So, you'll need about 3 quarts of stain.