How to measure knitting tension (gauge) accurately

Gauge (tension, in British patterns) is the number of stitches and rows you knit over a set width and height. American patterns usually give it per 4 inches, British ones per 10 cm. Every stitch count in a pattern depends on it, which makes it the most important number on the page. Get it wrong and the sweater comes out the wrong size, even if you follow every row perfectly.

Measuring it properly isn't hard. It takes a decent swatch and a bit of patience, and then you'll have numbers you can trust.

In a hurry?

1. Knit a swatch at least 6 in (15 cm) square, in the stitch the pattern names, on the needles you'll use for the garment.
2. Wash and dry it exactly as you'll treat the finished garment.
3. Let it dry fully and take out any pins.
4. Count stitches and rows over 4 in (10 cm) in the middle, in two or three places, counting half stitches.

The rest explains why each step matters, and what to do when your yarn won't cooperate.

Make the swatch bigger than you'd like

A swatch the size of a coaster is too small. The stitches at the edges are distorted, and you need to measure well away from them. Aim for at least 6 in (15 cm) square. Bigger is better.

How many stitches to cast on? Take the pattern's stitches per 10 cm and multiply by 1.5. If the pattern says 22 stitches to 10 cm, cast on about 33. If the stitch pattern has a repeat (say, a multiple of 4 plus 2), round to fit.

Add a small garter border. A few edge stitches in garter stitch (knit every row) at each side, and a few rows at the top and bottom, help the swatch lie flat. Don't measure across them, though: garter stitch has a different gauge from stockinette (stocking stitch).

Use the needles you'll knit the garment on, right down to the material. Metal, wood and bamboo needles of the same size can give slightly different results, because the yarn slides differently over each.

Swatch in the stitch the pattern names

Read the gauge line carefully. Most patterns give gauge over stockinette, but many vintage patterns give it over the main pattern instead: over the cable panel, the check, the lattice, the rib. If the pattern says "over pattern", knit your swatch in that pattern. A cable or textured stitch can pull the fabric in a lot, so a stockinette swatch tells you very little about it.

Flat or in the round? Match the garment

Many knitters purl a little more loosely (or tightly) than they knit. Flat stockinette is half knit rows and half purl rows; in the round it's all knit. So the same yarn on the same needles can give a different gauge flat and in the round. One designer, for example, recorded about 4.25 stitches per inch flat but 4.75 in the round with the same yarn and needle.

If your garment is knitted in the round, either knit a small tube or make a "speed swatch". Knit across on a circular needle, slide the stitches back to the other end without turning, carry the yarn loosely across the back, and knit the next row from the right side again. Cut the loose strands at the back before blocking (or leave them very slack) so they don't pull the fabric in.

Wash it, then wait

This is the step people skip, and it's the one that catches them out. Wool relaxes and blooms when it's wet. Some yarns grow, especially in length, and some shrink. The gauge that matters is the gauge of the finished, washed garment. Modern patterns usually give gauge after blocking. Vintage patterns rarely say, so assume they mean the finished fabric.

• Hand-wash the sweater? Hand-wash the swatch.
• Machine-wash it? Machine-wash the swatch.
• Lay it flat to dry. Pat it into shape but don't stretch it, unless it's lace, which you'll block open just as you will the garment.
• Wait until it's completely dry. Then take out any pins and let it rest for a while before you measure.

It helps to measure before and after blocking too. If your swatch changes a lot, you'll know to measure the garment pieces after washing as well.

Count stitches and rows

Lay the swatch flat on a table (not on your knee) without stretching it.

Stitches. Place a ruler horizontally across the middle. Put a pin at the start of a stitch and another exactly 4 in (10 cm) along, then count the Vs between the pins. Each V is one stitch.

Rows. Turn the ruler vertical and count the Vs stacked in a single column over the same distance. Each V is one row.

Measure in two or three different places and average them. Swatches aren't perfectly even, and one measurement can mislead you.

Count half stitches. If your measurement ends halfway across a V, that's half a stitch. It sounds trivial. Over a whole garment it isn't, as the example below shows.

A ruler is better than a tape measure, which can stretch. A gauge ruler with a 10 cm window is handy too.

Why one stitch matters

Say a pattern is written at 22 stitches to 10 cm, for a sweater measuring 100 cm around the chest. That's 220 stitches around the body (2.2 stitches per centimetre × 100 cm). Here's what those same 220 stitches measure if your gauge is a little different:

Just one stitch per 10 cm changes the chest by more than 4 cm, or about 1¾ in. That's often the difference between a neat fit and a tight one. Even half a stitch moves it by over 2 cm.

Rows matter too. Suppose an armhole is meant to be 20 cm deep at 30 rows to 10 cm, so the pattern says work 60 rows. If you knit 32 rows to 10 cm, those 60 rows measure 60 ÷ 3.2 = 18.75 cm, more than a centimetre short. Wherever a pattern counts rows (raglans, sleeve shaping, sleeve caps, colourwork charts), row gauge changes lengths and shapes.

If your gauge is off

Change the needle size, not your knitting. Knitting tighter or looser on purpose rarely stays consistent across a whole garment.

Then knit and block a new swatch. Don't guess what the change did; measure it.

Often you can match stitches but not rows. With a normal pattern, match the stitches, then work to the measurements given rather than the row counts, adjusting any row-based shaping. With our patterns you don't need to match the original at all: you tell us your stitches and rows, and the pattern is calculated for them (within the range of gauges that suits each design).

Awkward swatches

Garter stitch. Each ridge is two rows. Count ridges and double them, and watch for an odd row sitting on the needle at the top.

Cables and textured patterns. Cables pull in, so measure over the pattern exactly as the gauge line describes. Some patterns give gauge over a set number of stitches ("one 24-stitch panel measures 8 cm") instead of per 10 cm. If so, measure the panel width and work out stitches per 10 cm from that.

Stranded colourwork. Colourwork is usually firmer than plain knitting in the same yarn, and floats can pull in. Swatch in the colourwork, ideally in the round if the garment is, and keep the floats relaxed.

Mohair, bouclé and fuzzy yarns. The stitches can be almost impossible to see. Two tricks help: - Place a marker (or a loop of contrast thread) between stitches as you knit, work an exact number of stitches, place another marker, then measure the distance between them instead of counting. - Or count the total stitches and rows in the whole swatch (not the borders), measure its full width and height, and divide. For example, 40 stitches over 18 cm gives 40 ÷ 18 × 10 = 22.2 stitches per 10 cm.

Holding a fuzzy swatch up to the light can make the stitches easier to see, too.

Lace. Block it open firmly, just as you'll block the garment. Let it dry, unpin it, let it settle, then measure.

Before you trust your numbers

Run down this list. Each one is an easy slip:

• Swatch too small, so you end up measuring the distorted edges.
• Measuring on the needles, or before blocking.
• Stretching the swatch flat as you measure.
• Swatching in stockinette when the pattern gives gauge over a cable, check or lattice pattern.
• Swatching flat for a garment knitted in the round, or the other way round.
• Ignoring half stitches.
• Forgetting rows. Row gauge changes lengths, sleeve shaping and armholes.
• Using different needles (or a different yarn or colour) for the garment than for the swatch.
• Measuring once instead of in a few places.

Your gauge can also drift once you relax into a project, so measure the garment itself after the first 4–6 in (10–15 cm).

What to type into our site

When you buy a pattern from us, you enter two numbers: your stitches and your rows, measured over 4 in or over 10 cm (you choose which, and we do the conversion). Measure them over the stitch the pattern names (usually stockinette; some designs say over the cable, check or lattice pattern), on the needles you'll use, after washing and drying your swatch. Half stitches are fine: 22.5 is a perfectly good answer.

Just make sure you pick the right one. 4 in is a little longer than 10 cm (10.16 cm), and over a whole sweater that difference adds up to more than 1.5 cm around a 100 cm chest.

Your swatch, your pattern

Most vintage patterns ask you to match the designer's gauge. Ours start from yours: each one is rebuilt from the original written instructions for your size, yarn and gauge, in US 4–24 / UK 8–28 (32–52 in bust). Every design was chosen and checked by a knitter, and if you get stuck, email support@vintagetomodernknits.com and a real person will answer.

Read next

• Tension to yarn weight tool
• Resizing vintage knitting patterns
• Old knitting needle sizes
• Will it fit? tool

Last updated 2026-10-11.