Common measurement errors in knitting patterns
Knitting patterns are instructions for making an item that is exactly like the item created by the designer. Naturally, measurements are a key part of that equation.
Here are some common measurement issues that I see when tech editing knitting patterns.
Multiplying by 2.54 to convert inches to cm
In the real world, 1 inch = 2.54 cm. But in the knitting world, 1 inch = 2.5 cm. Why? Because gauge is often given in 4 inches/10 cm. That’s a 1:2.5 ratio, not a 1:2.54 ratio. This means that all of the other measurements in the pattern should follow that same ratio, because EVERYTHING in a knitting pattern is based on gauge.
This is a simplified, high level explanation, but I wrote a blog post about this a while back if you’re interested in diving in deeper.
If you’ve been converting without considering this, then I highly recommend switching over to 1:2.5!
Listing measurements that aren’t measurable on a ruler
Inch rulers are divided into eight lines (or sometimes 16), while the centimeter side is divided into 10 lines. So you can’t technically measure 1.25 cm other than to just eyeball between the .2 and .3 marks. Likewise, it would be hard to measure 2.8” on a ruler. Therefore, it’s best to list inches in quarters of an inch and cm in tenths.
I recommend listing inches in quarters, halves, or full numbers and cm in halves or full numbers.
Not giving both Imperial and Metric measurements
If you’re in the US like me, I know it can be so easy to default to thinking in Imperial because that’s what we’re accustomed to. But, by only including inches in your pattern, you may be excluding international knitters!
For me personally, if I see a pattern only lists cm, I click out real fast because I don’t want to be dealing with doing all of those conversions myself.
So, while it’s not technically an “error” to not list both, I recommend it simply because you can expand your reach by including both measurement systems.
Just gonna leave this related SNL skit here…
