Something to be aware of - the app very helpfully alerts you to this - a full circle skirt (such as this one) is just that - a big circle with a hole in the middle for your waist, so your fabric needs to be wide enough that you could cut the full circle out of it unless you want seams in strange places. 60" wide fabric is what to look for unless you are going super short and risqué :)
You'll want a fabric with some body and lots of drape unless you're going to a very stiff and sticky outy sort of look. The orange fabric I used is a loose weave polyester I think, I mostly got it because of the colour if I'm honest, but it hangs very nicely as you can see in this slightly less swooshy picture:
So - what to do. I took the pictures when I did the lining so that's why it's not bright orange!
Firstly, you'll want to mark out your skirt shape. I did this using the very high tech method of a bit of string and a pencil combined with my tape measure. The fold line for the fabric is at the bottom of this photo, selvedges matched up on the left:
I took the 'radius' measurement I got from the BHL app and measured that distance from the bottom left corner of my folded fabric down along the fold line. I secured the string at said length, tied it to the pencil, then drew and arc using the string to guide me so the line was the right length all the way around. I then did the same with the 'length' measurement from the app added on to the 'radius' measurement, then made another arc to add a bit more seam allowance - you can just about see those lines in pink on the photo below arcing up to the top right corner.
Once I had my lines drawn out I then cut out the shape I had created and got the shape below (this is good for a full circle skirt). Because the fabric is folded along the bottom edge, it will fold out into a full half circle, and you need to cut two like this. The BHL app shows you the layout to get two of them out of one piece of fabric, which is very handy.
I'd decided I wanted a nice wide waistband on this skirt as a bit of a feature (and I have to say it's one of my favourite things about it). To do that, I measured my waist, added 2 inches for plenty of seam allowance and ease then divided that figure by two (we'll call this measurement 'A' just for simplicity)
For the mathematicians amongst you that's (waist measurement + 2")/2 = A
I then just eyeballed how wide I wanted the waistband to be using my cutting matt. I decided 3 inches would be about right, so I cut two strips of fabric on the fold that were 4 inches wide (allowing half an inch on both sides for seam allowance) and 'A' long. I used a rotary cutter and ruler for this and it's a lot easier than using scissors.
So that's all your pieces!
To sew the skirt together is very simple, just sew together your two half circle pieces down one of the short straight sides to create one massive piece that would create a whole circle were you to join that other side up. You don't want to sew this up yet because you'll need to put a zip in and that needs to be attached to the waistband, which we will attach next!
To complete the waistband I pinned one of the waistband strips along the long edge to the top of my circle skirt piece (the smaller arc) , matching the raw edges to the open seam on the skirt and sewed it in place again with a half inch seam allowance. It should look something like this when it's done...
Now to attach the zip! I'm not going to go into detail here about how to insert a zip because that would probably warrant its own post but you'll need to make sure the top of the zip stop is half an inch below the top of your waistband piece and sew it in place, then finish off the side seam below it. If you'd like a great tutorial about how to insert a zip into a skirt with a waistband take a look at my previous post about this free zip class on craftsy.
At this stage you should have something resembling a skirt - it's got a waistband piece, and the skirt itself has a zip and you can put it on and take it off whilst keeping your dignity firmly intact. Only problem is your waistband piece is a single thickness and there's a lot of raw edges on the inside which won't look very nice and might scratch you if you're not careful.
To make sure the waistband doesn't look all raggedy on the inside you'll need to 'face' it - this means putting another piece of fabric on the back to hide the raw edges. Take your other waistband strip (yes it was all part of the plan!) and fold over about 1cm along one of the long edges and just iron it down so it stays in place. Then you need to stitch the other (unfolded) long edge to the top edge of your waistband piece that is already attached to the skirt, using a half inch seam allowance again and sewing right across the top of your newly inserted zip. It will look a bit like this, with some artistic license needed to account for the skirt actually being almost a full circle rather than a trapezium and the two side seams are now sewn up:
Fold the top waistband piece to the inside of your skirt and you should find that your neatly ironed edge will just cover your seam line from attaching the first waistband piece to the skirt body - pin it down all the way around to cover that line. You'l now need to flip it over so you're looking at the right side of the skirt, and sew right along the seam line between the main skirt body and the waistband - try and keep right in the 'ditch' if you can so you can't see your stitching. This is called 'stitching in the ditch' and it will catch you ironed and folded edge on the inside of the skirt so it looks all lovely and neat when you turn it inside out. If you don't fancy that, you can hand slip stitch your waistband along the inside to secure it down.
Now - this is the tricky bit because you'll want to put it on and spin around in it - leave your skirt hanging up for a good 48-72 hours. The fabric at the front and back will now be on the bias and is likely to stretch out a bit. If, like me, you are impatient and sew it straight away, you'll probably end up with a wonky hem after a little while as the fabric stretches out. Personally I don't mind because the style of skirt is so loose and flowing that you can't really tell, but technically, you should hang it up for a bit before you hem.
Then just spend a few hours hemming (circle skirts do take forever to hem because the distance around the bottom is so long) and you'll be done! Make the hem as narrow as you can, it will make your life a lot easier, on this version the hem is probably only a quarter of an inch deep. I zig zagged the raw edge of the fabric and then turned it up as little as I could just to hide the zig zag, it worked pretty well and hemming was straightforward, if lengthy.
So that's it! If you're new to sewing there's a bit of stuff in here that you'll need to practice I expect but the actual sewing is fairly simple, all straight lines for the most part, so it's a really good beginner project, once you've sewn together a few other items.