How to use the knitting gauge calculator
- Knit a swatch and measure it after blocking. Enter the number of stitches across it and its width, and the rows and height.
- Enter the wanted width and, if you need the rows, the wanted length of the finished piece.
- In the advanced fields, set a stitch pattern multiple so the cast on fits your pattern repeat, and add edge stitches.
- To follow a pattern written for another gauge, enter the pattern gauge and a stitch count to convert it.
Formula
Stitches per inch = swatch stitches / swatch width
Cast on = stitches per inch x wanted width + extra stitches, rounded to the pattern multiple
Rows = rows per inch x wanted length
Converted pattern count = pattern count x your gauge / pattern gauge
Rows per inch come from the swatch rows and height in the same way. Use inches or centimeters, but not a mix.
Worked example
A swatch has 22 stitches over 4 inches, so the gauge is 5.5 stitches per inch. To knit a piece 20 inches wide, you cast on 5.5 x 20 = 110 stitches. With a multiple of 8 it rounds to 112.
The same swatch has 30 rows over 4 inches, which is 7.5 rows per inch. A 26 inch length needs 195 rows. A pattern that calls for 20 stitches over 4 inches with a count of 100 becomes 110 stitches at your gauge of 22 over 4 inches.
Why you knit a swatch
Everyone knits at their own tension. Two knitters using the same yarn and needles can end up with sizes that differ by a full size. A swatch tells you your real stitches and rows per inch so the finished piece comes out at the size you want. Wash and block it as you will the finished item, then measure across several inches for accuracy.
Matching a pattern repeat
Many stitch patterns repeat across a fixed number of stitches, and a cast on needs to fit the repeat plus any edge stitches. The tool rounds the exact count to the nearest multiple you enter, then shows the width that actually results so you can see how far it moves from your target.
Other crafts
Fabric crafts use the same idea. For cross stitch sizes see the cross stitch size calculator, and for quilting yardage use the quilt backing and binding calculator. Unit changes between inches and centimeters can be done with the unit converter.
Assumptions and limits
- Gauge is the same across the whole piece. In practice it can change with stitch pattern, shaping and the weight of the fabric.
- Measurements are taken from a blocked swatch in the same stitch pattern you will use.
- The cast on is rounded to the nearest multiple you enter. Shaping, ease and seams are not modeled.
- Rows are rounded to the nearest whole row.
Frequently asked questions
How do I calculate how many stitches to cast on?
Multiply your stitches per inch by the width you want in inches, then adjust to your pattern repeat.
What if my gauge does not match the pattern?
You can change needle size to match, or adjust stitch counts. This tool scales a count from the pattern gauge to yours, but shaping may still need care.
How big should a gauge swatch be?
At least 4 by 4 inches, or 10 by 10 centimeters, measured away from the edges. Larger is more accurate.
Should I wash the swatch before measuring?
Yes, treat it as you will treat the finished piece. Many fibers change size after washing and blocking.