Gauge is the number of stitches and rows in a measured square of your knitted fabric

Gauge is how many stitches and rows fit into one inch (or sometimes 10 centimetres) of your finished knitting. A pattern tells you what gauge it was designed for — usually written as "18 stitches and 24 rows over 4 inches on US 6 needles" or similar. If your gauge does not match the pattern's gauge, your finished garment will be the wrong size.

Measuring gauge correctly takes five minutes and prevents hours of ripping back. The most common mistake is measuring too close to the edge of your swatch, where stitches are often loose or distorted. The second mistake is measuring before the fabric has been washed and dried the way you plan to finish the actual garment — some yarns shrink or relax significantly.

You do not need special tools. A ruler and a piece of scrap yarn work. A gauge ruler (a small metal ruler with a window cut out) costs a few dollars and makes the job faster, but it is not required.

Key Takeaways

  • Knit a swatch at least 6 inches square using the yarn, needles, and stitch pattern from your project, then wash and dry it the same way you will finish the garment.
  • Measure the number of stitches across 4 inches in the middle of the swatch, away from the edges where stitches are often loose.
  • Count the number of rows in 4 inches vertically, using the same middle section of the swatch.
  • If your stitch count is higher than the pattern calls for, your stitches are too tight — try the next size up needle; if lower, they are too loose — try the next size down.
  • Measure gauge after washing and drying your swatch, because many yarns change size during that process.

How to knit a gauge swatch

Cast on enough stitches to make a square at least 6 inches wide. If the pattern calls for 18 stitches per 4 inches, that is 4.5 stitches per inch, so cast on about 30 stitches to give yourself a 6-inch-wide swatch. Knit in the stitch pattern from your project — if the pattern uses stockinette stitch, knit stockinette; if it uses ribbing or cables, knit those.

Knit until the swatch is at least 6 inches tall. This takes 10 to 15 minutes for most swatches. Bind off loosely so the edge does not pull in and distort your measurement. Do not measure the swatch yet.

Wash the swatch the same way you plan to wash the finished garment. If the pattern says hand wash in cool water, do that. If you plan to machine wash, machine wash the swatch. Lay it flat to dry or hang it, depending on what you will do with the finished piece. Some yarns change size noticeably during washing — cotton often shrinks, while some synthetics relax and grow.

Measuring stitches per inch

Lay the dry swatch flat on a table. Using a ruler or gauge ruler, measure 4 inches horizontally across the middle of the swatch — not near the cast-on edge, the bind-off edge, or the side edges, where stitches are often loose or uneven. Mark the start and end of your 4-inch span with pins or a piece of yarn.

Count the number of stitches between your two marks. Count the bumps on the front of the fabric (in stockinette stitch, these are the V-shapes). Count carefully — missing even one stitch changes your gauge. Write down the number.

If you counted 18 stitches in 4 inches, your stitch gauge is 18 stitches per 4 inches, or 4.5 stitches per inch. The pattern will tell you what it should be. If the pattern says 18 stitches per 4 inches and you have 18, your stitch gauge matches.

Measuring rows per inch

Using the same swatch, measure 4 inches vertically down the middle section. Mark the start and end with pins or yarn. Count the number of rows between your marks by counting the horizontal lines of bumps running across the fabric.

Row counting is trickier than stitch counting because rows are less obvious, especially in textured stitches. Count slowly and recount to make sure. If you counted 24 rows in 4 inches, your row gauge is 24 rows per 4 inches, or 6 rows per inch.

Write down both numbers: stitches per 4 inches and rows per 4 inches. You now have your actual gauge. Compare it to the pattern's gauge.

What to do if your gauge does not match

If you have more stitches in 4 inches than the pattern calls for, your stitches are too tight. Your finished garment will be smaller than intended. Go up one needle size — if you used US 6 needles, try US 7 — and knit another swatch. Wash, dry, and measure again.

If you have fewer stitches in 4 inches than the pattern calls for, your stitches are too loose. Your finished garment will be larger than intended. Go down one needle size and try again.

Keep adjusting needle size and re-measuring until your gauge matches the pattern within one stitch per 4 inches. Matching row gauge is less critical than matching stitch gauge — a small difference in rows usually does not affect fit — but it is worth trying to get both close.

Using a gauge ruler for faster measuring

A gauge ruler is a small metal ruler with a rectangular window cut out of the middle. Most windows are 2 inches by 2 inches or 4 inches by 4 inches. You lay the ruler on your swatch so the window frames the area you want to measure, then count the stitches and rows visible through the window.

The advantage is speed — you do not have to mark anything with pins or yarn. The disadvantage is that the window is small, so you are measuring a smaller area, which can make counting harder if your stitches are very small. A gauge ruler costs between $3 and $8 and is optional — a regular ruler works just as well if you are patient.

Gauge in different stitch patterns

Gauge changes depending on the stitch. Stockinette stitch, garter stitch, and ribbing all have different gauges even when knit with the same yarn and needles. Always measure gauge in the stitch pattern your project uses. If the pattern uses stockinette for the body and ribbing for the cuffs, measure gauge in stockinette, since that is what determines the overall size.

Textured stitches like cables or lace can be harder to measure because the stitches are less regular. Count as carefully as you can, measuring in the middle of a repeat of the pattern so you are not counting partial stitches at the edge.

Frequently Asked Questions

Do I have to measure gauge before every project?

Yes, if you want the garment to fit. Gauge changes with needle size, yarn, tension, and stitch pattern. Even if you knit the same pattern twice with the same yarn, a different needle size or a change in how tightly you hold the yarn can shift your gauge enough to change the finished size.

What if I do not have time to knit a full swatch?

Knit one anyway — it takes 15 minutes and saves you from spending 20 hours knitting a sweater that does not fit. You can use the swatch as a dishcloth or coaster when you are done measuring it.

Can I measure gauge on the project itself instead of a swatch?

Not reliably. The edges of a garment in progress are often loose or distorted, and you cannot wash and dry it the way you can a swatch. Measure on a separate swatch so you can adjust your needle size before you commit to the full project.

What if my row gauge is off but my stitch gauge is correct?

Stitch gauge matters more for fit. If your stitch gauge matches but your row gauge is off by a row or two per 4 inches, the garment will still fit — it might just be slightly shorter or longer than the pattern intended. You can adjust the length as you knit if needed.

Does blocking change gauge?

Yes. Blocking — pinning the swatch to shape while it dries — can change how many stitches and rows fit in an inch. If you plan to block your finished garment, block your swatch the same way before measuring gauge.