Gauge is a most important lesson, for if you do not attain the number of stitches and rows per inch as specified at the beginning of the pattern, your crochet project will not be the correct size. Imagine how disappointing it will be if the garment you are making turns out to be too large or too small, not to mention the many precious hours of work, plus cost of materials, that are wasted! Being off gauge even a half a stitch per inch can make a difference of several inches on the finished piece. Be sure to follow gauge exactly.

To check gauge: Crochet a sample swatch using the specified hook and yarn. Work the number of stitches and rows to measure a 4" square. Place swatch on a flat surface being certain not to stretch it as you measure 2" in both directions, marking positions with pins. Count the number of stitches and rows. If your gauge doesn't correspond to the one given, change hook size and work another swatch. If you have more stitches per inch than specified, try a larger size hook. Continue testing until you achieve the specified gauge.

Use whatever size hook will give you the correct gauge regardless of the size specified in the pattern!

These Two Swatches Are Exactly The Same Size!
Or are they?
These two swatches were made by two different crocheters. They used the same yarn, the same size hook and the same number of stitches. Note the difference in size! If they each made a sweater following the same pattern and using the hook indicated in that pattern the sweaters would be very different sizes.

No two crocheters work alike. The pattern writer does not crochet exactly as you do! The only way to guarantee the fit is to check your gauge. Remember: Use whatever size hook will give you the correct gauge regardless of the size specified in the pattern!