** Warning! Bit of an ultra-long-brain-required-halfway-through post. **
‘Crazy girl!’ I hear you exclaim. I concur.
If you’ve checked out my Ravelry profile, you’ll see I’m a bit more mad than that with six blanket projects in my works at the moment. But I made a hard decision to focus on only three. They are:
- The Star Anise Blanket
- Blanket Polka
- Blanket Scrabble
I’ve made a move on Blanket Scrabble. After working out what the plan was going to be two weeks ago, it was time to get started on the math. Here’s how I’ve worked it:
First we (me, myself and I) need to understand what the finished blanket is going to be. Cue graphic:
I’ve decided on the parameters for the yarn: It needs to be 8 ply, DK weight. It needs to be soft on the skin and last a lifetime, so no pure wools or acrylics. It needs to come in a range of colours so I’m able to buy the right ones! It also needs to be cost effective… If you’ve never made a blanket before (like me) you’ll know why soon!
I bought some great cashmere yarn from the craft department store, but it has a limited colour range and is being discontinued. However, it does meet all my requirements, so it will be a great sample yarn to work out the numbers. Speaking of which, we’ll need to know it was 100 meters in a 50 gram ball.
Count ’em in the plan, that’s 225 squares. It’s important that we choose the right kind of square. I want them to be the same all over the blanket so the centre of each square needs to be some kind of star, as an actual Scrabble board has a black star in the middle. I searched on Ravelry and the interwebs, through magazines to no avail. So I tried making a variation of the hexagon I’m using in the Star Anise Blanket and – success! I am happy.
I first tried with a 4mm hook, but since our squares need to be about 13cm x 13cm it was too small and a little tight. Upping the hook to 5mm made it the right size and floppiness!
Just a warning, if you’re not mathematically inclined and reading this with your morning coffee/after work/winding down for bed, this post ceases to be ‘easy-reading’ after this next heading…
Necessary evil in my view. So let’s get started.
We already know we need 225 squares, but how many of each colour? Count ’em:
- 8 Red
- 16 Pink
- 12 Dark blue
- 24 Light blue
- 164 Beige
- 1 Pink with black star
So! Back to the sample square, I unravel it 😦 ! and discover it takes 18.4m of yarn to make one.
And now for math…
With 100 meters in our sample ball, we can make about 5 and a bit squares with one ball (100m ÷ 18.4m = 5.4 squares). But we’ll get more accurate numbers with another calculation:
|No. of Balls
|No. of Balls
||8 × 18.4m =
||147.2m × 100m =
||2 + 1**
||17 × 18.4m =
||312.8m × 100m =
||4 + 1**
||12 × 18.4m =
||220.8m × 100m =
||3 + 1**
||24 × 18.4m =
||441.6m × 100m =
||5 + 1**
||164 × 18.4m =
||3017.6m × 100m =
||31 + 2**
* For making sure we have enough, we’ll include the pink and black star square in with the pinks!
** Just to be sure, add an extra ball or two! It would be awful to run out so close to the end, and the Stash needs to be cared for! 😀
Awesome! Now we have the first part of our shopping list, but there’s still the white yarn to work out, the yarn to join of the squares and add the border…
This one is different, we don’t have a square to unravel. But we do know that all the squares are going to be joined by a tr crochet. So how much thread do we use for one tr? Let’s make a stitch, mark the end with a pen. Unravel one stitch, mark the start with a pen. Measure between the two dots and… My tr stitch is 12cm!
Next question, how many stitches join one side of a square? We can count them with the picture, and I see 20 stitches. Right-o, how many stitches can we get out of a ball? A rude estimation of 830 stitches! (100m ÷ 0.12m = 833.3333333 stitches).
Now this is where my mind really started to wander, but stick with me…
We need 225 squares and each square has 4 sides; That’s 900 sides of squares (225 squares × 4 sides = 900 sides). But as we’ll be joining 2 sides of two squares, we’ll only stitch half that: 450 sides (900 sides ÷ 2 = 450 sides). Now, if 1 side takes 20 stitches, we’ll make 9000 stitches to join 225 squares (450 sides × 20 stitches = 9000 stitches). Excitement! So with a rude 830 stitches to a ball, we can say that we’ll need 11 balls! (9000 stitches ÷ 833.3333333 stitches = 10.8 balls, round it up to the nearest whole number!).
Finally, we work out the border. There are 15 squares along each side of the blanket. Each of those squares will be edged with 20 stitches, so along one side of the blanket there will be 300 stitches. (15 squares × 20 stitches = 300 stitches). 4 sides to the blanket; 1200 stitches (300 stitches × 4 sides of blanket = 1200 stitches). I want two rounds of tr on the border, so we’ll times this by two to get 2400 stitches (1200 stitches × 2 rounds = 2400 stitches). Again with the rude estimate of stitches to a ball, we can say 3 balls to do the border! (2400 stitches ÷ 833.3333333 stitches = 2.88 balls, round it up to the nearest whole number!).
This is where the brain protests and says ‘STOP! NO MORE MATH!’ So let’s say we want to add a final round of single crochet egding with picots or something, and chuck in another 2 balls and say that will be heaps.
Argh! So finally we can write the shopping list!
Climatic music with drum roll please…
- 3 Red 50g DK weight balls
- 5 Pink 50g DK weight balls
- 4 Dark Blue 50g DK weight balls
- 6 Light Blue 50g DK weight balls
- 33 Beige 50g DK weight balls
- 18 White 50g DK weight balls***
- 1 Black 50g DK weight ball
*** Yep. Throwin’ in two more for that Safe/Stash position!
Total 70 balls of yarn!! Dude this blanket better be loved. Now you see why it must be cost effective! I would not attempt this at $12.99 a ball on my current budget, if ever!!
After all this numberin’, A quick phone call to a known knitter made the helpful suggestion of working out how much it will weigh. In her experience, she said, it’s no good making up a jumper if no-one can lift their arms in it. So one last easy-peasy calculation: The finished blanket would weigh about 3.5 kg! ((50g × 70 balls) × 1000g = 3.5kg). An acceptable weight for a blanket methinks.
Armed with a shopping list, it’s now time to seriously consider what yarns to buy. I know the Internet is full of beautiful yarns, but I’m a beginner and new to this wonderful world of yarn so I need my purchase to be made in person. I need to know the yarn feels right before I fork out for 70 balls of it! This is going to be some hunt! More Country Drives!!
I really do feel like I’m getting somewhere with this blanket – And I hope my math and blanket calculations assist with that old
‘How long is a piece of string’ ‘How much yarn do I need for a blanket’ question. That said, if you’re better at math than me and notice something awry with my calulations above, please let me know! 😀
Oh my goodness! Now with all that math done, I’m going back to a freeform project for a while!
Stay creative 😀