How to fit stitch multiples in a row of knitting.

From, The Knitting Fiend (Lucia Liljegren) I'm compiling an index of calculators here.

If you've begun exploring stitch patterns, like those published in Barbara Walkers various Treasuries, you've come across this phrases like these:
  • "Multiple of 6 stitches plus 1"; (this is the multiple in the actual stitch pattern used in my Dewdrop Inn Dishcloth and Unbelievable Dishcloth. I added two selvedge stitches, so the dishcloths themselves require a "multiple of 6 plus 3". )
  • "Multiple of 11 stitches"; (gorgeous example by Christine.)
  • "Odd number of stitches";  same as multiple of 2 plus 1.
  • "Even number of stitches"; same as multiple of 2 plus 0.
  • "Any number of stitches"; same as multiple of 1 plus 0. 
This calculator will determine the closest number of stitches you need to knit to achieve a target width of knitting in any fancy stitch pattern you like.   To use the calculator, you will need to know the stitch gauge from your gauge swatch (or test square, as some call them).

Note: If you prefer metric, you can enter the width in cm, in that case, the stitch gauge must be in stitches/cm.

Enter width you need to the right.  inches. 
Fill in blanks from the instructions for your stitch pattern:  Multiple of   stitches plus .

Enter your stitch gauge to the right:
stitches/inch.

Results and Discussion:

There are three results, all of which can be considered correct.  Which you chose depends on the knitting project at hand.  Rounding up or down results in whole repeats of the stitch pattern. I always do one or the other when I'm knitting dishcloths or beautiful lose fitting lace.  Padding with extra stitches at the selvages results in the closest possible fit.  I often do this if I am knitting sweater.  Depending on the pattern, I might knit the extra selvadge stitches in stockinette, reverse stockinette, garter or seed stitch.
  1. Round down:
    • stitches; this will measure inches across.
    • Round up:
      •   stitches; this will measure inches across.
    • Pad with extra stitches:
      •   stitches.  Place a marker stitches in from the each edge. The stitches inside the markers are knit in pattern; the ones outside the markers are selvage stitches.   The piece will measure inches across.
      Have fun knitting!
      Lucia