Gauge and Swatching Explained

When you first start to knit you may not be aware of the concept of gauge. It can seem tricky enough learning how to cast on and create a knit and purl stitch, right? However, once you have mastered the basics and fancy knitting a larger project, such as a garment, it is important to spend some time looking into gauge and tension. There is nothing worse than spending hours and hours knitting away on a beautiful jumper then to realise that it’s come out way to small or big to wear!

Often the terms ‘tension’ and ‘gauge’ are used interchangeably and mean very similar, if not the same thing in the knitting world. Generally speaking, ‘tension’ refers to how tight or loose the knitted fabric is and ‘gauge’ is the measurement of tension – I.e. how many stitches and rows are required to create the fabric per unit of measurement (centimetres/cm2 or inches/in2). This is a really important concept to understand if you want to start creating garments and you want them to fit correctly.

Let’s break it down a little by looking at an example:

Someone could be considered a ‘tight knitter’ or have a tight tension when the fabric they create is ‘dense’ and they have a high number or stitches/rows per cm/in (tight gauge).

A garment knit with tighter gauge/tension than the pattern recommends would result in the item being smaller than expected.

Someone could be described as a ‘loose knitter’ or have loose tension when the fabric they create using the same needles and yarn has a low number of stitches/rows per in/cm (loose gauge). This results in a fabric more open fabric. A garment knit with looser gauge/tension than the pattern recommends would result in the item being bigger than expected.

A 'tight knitter' is the opposite. Generally speaking, new knitters will knit with a tighter tension as they get to grips with holding the yarn/needles and become confident with the new skills they are learning. This results in a fabric more closed fabric. A garment knit with tighter gauge/tension than the pattern recommends would result in the item being smaller than expected.

Knitting tension is very personal. Everyone knits at different tensions by nature and there are many variables that may affect tension such as the size of needle used and possibly the material they made from (e.g. wood or metal needles) or the type of yarn and fibre composition. The stitches/pattern used also have a great effect on fabric gauge. For example, cabled patterns create a tighter fabric compared to simple stocking stitch. Lace patterns often create a looser fabric.

What you need to know for gauge is how many stitches and rows are required to create a ‘size’ of fabric. This information is most commonly shown as the number of stitches and rows needed to create a 10cm by 10cm (4in by 4in) square. You also need to know whether the gauge was based on a fabric that was knit flat or in the round and if the gauge was measured on pain or patterned/textured fabric. It is important to test your own gauge in the same way as the pattern gauge you are trying to replicate.

Here is an example of how you may see gauge information displayed:

 “This pattern is knit flat with a gauge of 10 stitches and 20 rows = 10x10cm (4x4in) in garter stitch”.

When designers create a pattern, they measure their knitting to determine the gauge of the fabric. By working out how many stitches and rows there are in a unit of measurement. For example, how many stitches and rows are in 1cm2 or 1in2. Designers then work out how many stitches and rows are needed to achieve the garment measurements for each size in their pattern. This is why it is so important to check your tension and compare it to the pattern recommended gauge before starting a big project.

(For the knitter, gauge information is usually displayed over 10cm2 (4in2) as it is far more accurate to measure your stitches over a larger surface area).

If you create a fabric that has more or less stitches and rows per 10cm (4”) then your garment will end up a different size to what it should be. Using the example above, if the designer bases their measurements on 10 stitches for every 10cm (4in) but your tension is 12 stitches to every 10cm (4in), your garment will end up 20% smaller than intended. Likewise, if your tension is only 8 stitches to every 10cm (4in), your garment will end up 20% bigger.

Having a tighter or looser tension than the person who designed the pattern doesn’t mean you are doing it wrong or you are a bad knitter, it just means you knit slightly differently and will end up with different results. Therefore, you may need to make some changes to ensure you get a garment you will be happy to wear. We will go into more details on how to adjust gauge later. 

If your tension is looser (you have less stitches over 10cm/4in than suggested by the pattern), try knitting another swatch using a smaller needle. For example, if the pattern swatch suggests 4mm needles, try 3.75mm needles; or if your tension is tighter (you have more stitches over 10cm/4in than suggested by the pattern), try knitting another swatch using slightly larger needles than those suggested.

If need be, you can change up or down several needle sizes but do be aware of how this could affect the overall look of the fabric. The fabric may become tighter or looser than expected so it may be that the yarn isn’t working for you in the same way that it did for the designer. Or maybe you are not using the same yarn as the designer did. This isn’t necessarily a problem but there are extra things you should consider when substituting yarns as this could affect the outcome of your project.