Gauge Swatches -- The Basics

 It's important to check gauge prior to working any knitting project. If you are working to a pattern, you must match at minimum  the stitch gauge of the pattern. 

Stitch gauge is more important than row or round gauge (most of the time) because it's easier to compensate for length. It's almost impossible to compensate for width.

To make a gauge swatch, cast on enough stitches for at least 4" of the pattern being measured, then add a few extra stitches at each end. It's okay to make the swatch bigger. The bigger the swatch, the more accurate your measurement will be. 

Measure the gauge both before and after blocking. Be sure to note the numbers. 

Measuring Stitch Gauge: 

For simple patterns mark off a set of pre counted stitches. 

Measure these to the closest 1/8th inch.

Divide the number of stitches by the measurement to the closest 1/8the inch.

This gives you stitches per inch. Do not round this number-- leave it as is on your calculator. 

If working a pattern, multiply by 4. Then round to the closest whole number -- this is what you want to match your pattern's gauge. 

If your gauge swatch is too large—meaning you’re getting fewer stitches per inch than required—try again using smaller needles.

If your gauge swatch is too small—meaning you’re getting more stitches per inch than required—try again using larger needles.

For more complicated pattens such as cables and lace or other patterns where it's difficult to count stitches, mark off a set of multiples. Multiply the number of stitches in the multiple by the number of multiples marked off. For vertical patterns using spacer stitches, only use whole multiples -- leave out the extra stitches. For tessellated patterns without spacer stitches, use all multiples and extra stitches. Just be sure to add the extra stitches to your total stitch count when calculating the gauge. 

Calculating row gauge works in a similar way. Substitute rows for stitches in the above method. 

Here are some swatches with marking threads for examples: