Design a Crochet Granny Blanket :: Part Two ::

This is part 2 of a series of blog posts I'm writing to explain how I design my crochet granny square blankets, you can see part 1 here.

When you've chosen your yarn and once you've done a little swatching and decided what motif you're going to go with for your blanket, it's time to do some maths. Don't worry, it's nothing too scary.

The first thing you need to think about is how big your blanket is going to be. Single, double, lap, king, maybe it's for a baby. I used this source for a list of sizes. 

Next up, how big are your motifs? How are you going to join them? If you're going to use double crochet to join them together then your original motif size won't alter a lot, however if you're going to add another round of treble stitches to each square obviously this will make a big difference. I'm going to finish each square with a round of treble stitches in white and I'm going to use this round to join the squares together as I go. So when taking the measurement of my square I did it with the white border added. If you're going to block your squares you'll also need to do this before taking your measurement.

Once you have these two numbers, blanket size and square size you can work out how many squares you need, then you can weigh your motif to work out how much yarn you're going to need.

I have made a little spreadsheet you can download. You're welcome to use this to do all these sums for you, but I'll talk you through the sums so that you can also understand how these results are created.

Above you can see how the spreadsheet looks before you've entered any numbers. 

The first thing you need to do is plug in the numbers specific for your blanket. Firstly the details from your yarn, the grams and metres per ball as given on your ball band.

Next you need to add the size of the blanket you would like to make, so add your measurements to the line on the yellow table that reads 'Blanket Size' you can use whatever unit you like for this, whether it be cms or inches etc, but make sure you keep to the same unit for both your blanket measurement and your motif measurement. I recommend using cms but only because that's what I'm used to using myself. I'm aiming for a blanket that measures around 203cm x 228cm so these are the numbers I put in.
Next you add your motif size, my motif is square and measures 17cm x 17cm, so these numbers go in your yellow table where it reads 'Motif Size'.
In the second to last row you'll now be able to see how many motifs you need to make your blanket, this is a rounded number, as it's unlikely the size of your motif will fit exactly into the size you're hoping for, therefore in the row marked 'Finished Size' you can see what the measurements will be with the actual motif quantity.

So now we know how many motif's we need to make, but how much yarn do you need to buy?

There are two ways of working this out and I actually used both for my calculations. For the 6 colours that make up the main part of my motifs, I used the weight and for the white that surrounds my squares and joins them all together I used the length of the yarn used.

To calculate with the weight of your motif use the red table as follows; firstly weigh your motif using digital scales to get an accurate measurement. My squares, without the white border, weigh 15g so that's the measurement I enter in the first row of the table. As I aim to use 6 colours equally throughout the blanket I enter 6 in the second row. 

If you plan to use different amounts of each colour I'm afraid this table won't calculate that for you, but as you'll have the total number of balls needed, it shouldn't be too difficult to work out yourself. 

I calculated the quantity of white needed separately, as each square will have a round of this, therefore I will need white than any other colour. To do this I worked one round around my motif in white, then ripped it out! I then measured the length of the yarn I used. This measured 5.2 metres (520cms). Therefore this is the number that I put in the first row of the blue table. I'm only calculating for one colour here, so the second row is 1. I can now see that I need 12 balls of white yarn.

I now know that I need 8 balls of yarn in each of my 6 colours and 12 balls of yarn in white and I need to make a total of 156 motifs. Now to get to work on all those motifs!

In the next part I will share the pattern for the motif I'm using and explain how I'm joining my motifs as I go.

You can see Part 1 of this series here.

Design a Crochet Granny Blanket :: Part One ::

Since I've just started on a crochet granny blanket this week, I thought I'd share with you the steps I take in planning my blanket, so that you can design your own crochet motif blanket too, if you like. Thinking about the type of yarn to choose, the kind of motif you want to use, how much yarn you'll need, the process of blocking, weaving in ends and finishing your blanket to a beautiful standard.

I know you can simply grab a ball of yarn, a hook and just get going, without doing any of this preliminary fussing and by all means if that works for you then go right ahead, however, for me, I know if I plan everything out from the beginning I'm more likely to end up with the result I had hoped for. Let's be honest a blanket of any size is no quick project, so if you're going to invest all that time into it, you want to be pleased with the finished result.

Yarn Choice :

The first thing you want to think about is the yarn you're going to use. There are so so many options available to you; what fibre are you going to use, what colours and what kind of price point? I am fully aware of how quickly yarn costs can mount up when making a blanket, I've jumped straight in to blanket making without any forethought only to realise on my 4th trip to the yarn shop quite how expensive the finished product was going to end up being. Obviously if you can afford to, I fully endorse spending all the money on the most luxurious yarns to create an unbelievably decadent blanket, but I know that that is rarely an option.

The fibre you hope to use is of course going to have an impact on your budget. A blanket made from a silk, cashmere blend is obviously going to cost you a lot more than one made from 100% acrylic, but cheap does not have to be acrylic, there are many budget options available in natural fibres.

Another consideration is obviously who is going to be caring for the blanket? Are they likely to shove it on a boil wash after it's first use, turning into a super thick rug for a borrower, if you use a delicate pure wool? If so then you'll probably want to think about using a robust super wash or acrylic blend.

Now for yarn weight, by which I mean thickness of the yarn. Again so many choices from fine lace to super chunky. Definitely think about how long you hope to work on this project at this point. I would never, ever dream of crocheting up a blanket in lace, I just do not have the patience, but that doesn't mean you shouldn't, a lace weight blanket would be so lovely and drapey and delicate, but for me a double knit or aran weight yarn is much more achievable.

For this project I chose DROPS Alaska, for a few reasons, firstly it's a chunky Aran weight (I know watching this blanket grow quickly is going to spur me on to the finish line) however it's not so chunky that it'll be stiff and too heavy. It's 100% wool, but it's not itchy or rough, in fact it's really quite soft and lovely. I would much rather use a natural fibre over acrylic, though would definitely have considered a blend. It's got a lovely thick twist on the ply, meaning the stitch definition is really nice and it's really very cheap! Currently on offer at Wool Warehouse, it's only £1.20 a 50g ball.

To start out I just ordered one ball in each colour that I liked the look of, just in case I decided against the yarn or the colour, I wanted to have a play with the yarn before I took the plunge and invested lots of money.

I chose 6 colours, plus white, as I plan to edge each motif in white when I join them together. I don't think you can have too many or too few colours really, it's entirely up to your personal preference. I use pinterest as a great source of inspiration when I'm thinking about colour combinations.

Motif Choice ::

Another big choice to make, what motif are you going to use for your blanket? A regular straight up granny square, a hexagon, a triangle, will it have a puffed, 3D centre? I use all sorts of sources for finding motif ideas, including books, pinterest and ravelry.
Once you've got your hands of a couple of balls of the yarn you intend to use, you can start playing around with ideas and swatching up some motifs. Initially for this blanket I was going to use a regular granny square, but after a little bit of swatching I decided on a circle centre, with a squared off edge. I took a pattern I found online, but altered the last round a little in order to square it off a bit more, as I wasn't happy with the original result. Definitely play around with ideas until you really find something you love, after all you'll likely be making a whole lot of them!

Once you've made these big decisions, you can work out how big you want you blanket to be and calculate how much yarn you're going to need. I'll cover these elements in part 2.