How to calculate stretch percentage

How to calculate the stretch percentage of jersey fabric // Megan Nielsen Design Diary

In my sewing patterns created for stretch fabrics i often talk about the required fabric in terms of stretch percentage. For example, in the Briar tee pattern i say that you need to use a fabric with at least 20% stretch. For my maternity patterns i generally suggest fabrics with at least 40% stretch.

I feel like this is the best way of explaining exactly how stretchy your fabric should be to work with the design, but i know that if you’re not familiar with that measure it can be a little confusing. Thankfully it’s really really simple to calculate!

Your stretch percentage is just the width of your fabric when stretched to it’s maximum divided by the width of your fabric when unstretched (minus 1).

For example in the example shown below the stretch percentage would be 16/10-1 = 0.6 . This means the stretch percentage is 60%.

I find a very simple and quick way to calculate stretch percentage without a calculator is to keep the fraction simple. So I take a swatch of fabric and hold it width ways next to a ruler, tape measure or cutting mat, with my fingers placed at 0 and at 10 (it doesn’t matter if you’re using CM or inches, 10 is just a very easy number to use mentally). I leave my left hand static and stretch the fabric held by my right hand. That way i can very easily read off the number and mentally calculate the percentage.

So again with my example below, i can see at a glance that the stretch percentage is 60%.


One of the reasons i love talking about stretch percentage rather than the specific fabric content in our pattern requirements, is that it makes it easier to understand how you can manipulate the fit of your garment.

For example with the Briar, if you choose a fabric with a high stretch percentage, your garment is going to sit differently, more loosely. If you choose a fabric with a lower stretch percentage than required, it will fit more tightly and may be a little harder to get on and off. With the Briar this isn’t a big deal since it’s quite loose fitting. I often use sweater knits that have a lower stretch percentage and just accept the fact that i will either need to size up, or they will fit a little more snuggly. But on the other hand, one of my most upsetting makes ever was when i sewed up a pair of Virginia leggings with a very comfy fabric and forgot to check the stretch percentage before sewing. I couldn’t get them on! Considering i was pregnant at the time it was really really upsetting (cue me freaking out about pregnant weight gain) until i realised that the fabric had only 10% stretch when i needed 40% hehehe

Lesson here: Always check your stretch percentage babes!

tutorial: how to make a ruffle off the shoulder dress


Hey guys! Holly here, again. You all know how much I love all of my Megan Nielsen Pattern makes, but I wanted to take a minute to share with you something a little different today. I’m obsessed with the off the shoulder trend going on right now, and realized it would be super easy to make! So would you mind if I share a little tutorial with you? It’s really simple to draft the patterns, as it’s only a few rectangles. Add some elastic, and voila! A super on-trend piece that will make you feel oh-so fancy.


All you need is:

aprox 1 1/2 – 2 yards of fabric

1/4 wide elastic

sewing machine

iron and ironing board

scissors, measuring tape, pins, etc.


So come on makers, check out the tutorial after the jump!

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why its important to press stretchy fabrics

The importance of pressing stretchy fabrics // Megan Nielsen Design Diary

I’m often asked for tips on how to improve when it comes to sewing with knits – and this is one of those things that is incredibly simple and will really take your knit sewing to the next level.

Press your knits. That’s right, pressing during construction is not just important for wovens, don’t forget the stretchy fabrics!

This week i was making some leggings for Bunny with knee patches – the picture on the left is a leg that wasn’t pressed yet. Look at how wavy and puckered the heart is. It looks terrible. It looks homesewn, and not in the good way. Many people finish at this point and feel disappointed that it didn’t turn out how they had hoped. Thankfully it’s easily fixed if you remember to press!

The leg on the right is post pressing. Pressing the knee patch helped the fabric to recover after being stretched when i sewed it. It brought everything back into shape and set it so it will continue to look this good.

Pressing is crucial to every project. You absolutely 100% will not end up with a good result in sewing if you don’t press. This rule holds true for every fabric type, and there is no such thing as a garment you can get away without pressing.

It bears mentioning again – press everything. It’s my golden rule.

[For more on pressing and why it’s so important, check out this post]