(This post was updated on August 8, 2019)
“How to Measure Knitting Length is one of my most popular posts. When I began knitting, I found that many resources didn’t show how to measure your work. Perhaps the assumption was that measuring was easy to figure out, but asking how to measure knitting is a very good question.
A sewer would never be without a tape measure, and neither should a knitter. Use a flexible, undamaged tape measure marked with inches and centimeters. Be consistent throughout your project by using either the metric (centimeters) or imperial (inches) system. Measuring a garment back in centimeters, and the front in inches will result in the pieces not matching up when it comes time to sew them together. The small difference between the two systems does affect measurements.
Measuring Knitting Length
To measure the length of knit fabric worked on straight needles, lay the piece on a flat surface, such as a blocking board or a low pile carpet. A blocking board is one of the best surfaces for measuring. Don’t place the piece on a slippery surface like a wood table top, and don’t use your lap to measure. These types of surfaces will give inaccurate measurements. Without stretching the work, smooth the surface of the knitting, evenly spacing the stitches around the center of the needle. It’s easy to smooth out small pieces, or a narrow piece like the one in the image below. Alternatively, when there are a large number of stitches on the needle, work to the center of the row, then smooth out the piece. A fully ribbed piece is tricky to measure because of its elasticity; stretch a little to reveal the pattern unless the instructions indicate otherwise. After smoothing the piece out, you are ready to measure. In the centre area of the work, place the tape measure from the base of the needle to the bottom edge or the beginning of the work (cast on edge). Note: Read the pattern carefully because some instructions might say, measure to the last row of the border, or some other variation of this.
To measure the depth of a shaped armhole, measure perpendicular to the bottom edge, positioning the tape from the base of the needle to the first bound off row of the armhole. If there are many stitches, work to the center of the row, lay the piece flat, and measure from this point to the first bound off row of the armhole. Make sure not to follow along any shaped or slanted edge. When measuring sleeve length, measure from the center at the base of the needle to the lower edge, and not along the slanted side edge. Following along a shaped or slanted edge results in erroneous measurements – armholes too shallow and sleeves too short.
When working in the round, measuring length is not quite as easy as with straight needles. Smooth out the knitting hanging from the needle, or from the flexible wire portion of the circular on a flat surface. Measure from the base of the needle or wire in the center area to the lower edge. With stitches on double pointed needles (dpns), place one of the needles with stitches over top the other needles, and smooth out the work to shape. Place the tape from the base of the needle in the center to the edge of the area you’re measuring. For example, when measuring the foot of a sock, place the tape from the base of the dpn to the back of the heel.
Do you need to measure knitting width?
If the gauge of your test swatch is accurate, measuring the fabric width is not necessary. However, it’s a good idea to measure the width of your knit fabric when the work is approximately six or more inches in length, to check that your stitch gauge is still the same as the test swatch. It is more accurate to measure width further away from the cast on edge, because knitting tends to be tighter close to this edge.
To measure the width of knitting on straight or circular needles, smooth out the bottom section of the piece. Place the tape across the fabric from edge to edge, and not too close to the cast on edge. With a large number of stitches on straights, work to the center of the row, smooth out the work, then measure the width.
Measuring the length of your knitting in progress is a necessary step, and measuring its width is a good way to check if the stitch gauge is still accurate. The above information will help you to measure your work properly.
Bonus Material – Conversion Factors
To help you read yarn labels and pattern instructions, and to substitute yarn, here are some simple math calculations to convert between the metric and imperial systems of measurement.
Imperial to Metric
inches (in) x 2.5 = centimeters (cm)
yards (yd) x 0.9 = meters (m)
ounces (oz) x 28 = grams (g)
Metric to Imperial
centimeters (cm) x 0.4 = inches (in)
meters (m) x 1.1 = yards (yd)
grams (g) x 0.035 = ounces (oz)
A typical 50gram ball of yarn equals 1.75 ounces, and a 100gram ball equals 3.5 ounces.