Offset printing ink calculation formula

The formula for calculating how much ink will be consumed on an offset printing press is a formula that takes into account 5 variables.  It is referred to as the SPANKS method.  Each letter represents a number to multiply.  Then everything is divided by 353.  Here is what each letter signifies:

S x P x A x N x K x S / 353 = consumption in kilograms.

(S) This is the type of STOCK that will be used.  High quality coated =1.0; Low quality coated =1.2; Offset, wove or bond =1.3; Smooth cartridge=1.6; Newsprint=1.8; Rough cartridge=2.2.

(P) This is the PROCESS that will be used.  Offset printing=0.5; Letterpress=1.0.

(A) This is the AREA of the printed sheet.  This needs to be entered in square meters.

(N) This is the NUMBER of sides being printed.

(K) this is the KIND of image.  It represents the coverage of the sheet. Solid coverage =1.0; Halftone images 0.5; Light coverage 0.2.  This number is essentially and estimation of the coverage between 0 and 1.

(S) SPECIFIC gravity of the ink. Black=1.0; Reflex blue-1.2; Process colors=1.3; Red, blue or greet spot colors=1.4; Opaque white=2.0.

 There are also tests to determine the mileage from an ink.