Sewing Pattern Instructions – Flared Trousers

Welcome to the Free Flared Trousers Sewing Pattern instructions post, if you are interested in the design, it’s your lucky day!

To draft this pattern we are going to use the Slacks Foundation so if you haven’t drafted this pattern yet, click on the image on the right and do that first!

It is very important to correct the fit of your foundation before starting, as this design fits closer to your body. I advice you to make a prototype before cutting into the real fabric to avoid surprises!

I chose the Slacks foundation because it has a nice shape and at the same time the crotch is not too tight. Feel free to use any other foundation although I would advice you to use either the Slacks or the Jeans. The rest will be too baggy.

This is more of an advanced design, so get ready to stop feeling like a beginner! Let’s start with this Free Flared Trousers Sewing Pattern

SLACKS

Step 1 - The Front

Step number one is to change the shape of the trousers into the design we want

  1. Copy the front pattern and make sure to add the hip, crotch, knee and crease line
  2. Divide the block into two panels by using the crease line (If you have a dart, transfer it to the centre of the front waistline)

 

The crease line divides the pattern halfway at crotch level but not at waist level. To correct that, find the middle of the waist and connect it to the crease line.

  1. Draw a horizontal line 1.25cm below the ankle line
  2. Mark a point on that line 4cm away from each side of the ankle line
  3. Create a curve that goes from point to point and touches the ankle line where it crosses the crease line
  4. Draw the flare from the knee line to the edges of the curve

 

The last detail to add to the front pattern is the opening, in this case the fly:

  1. Go out 4cm from the centre front (CF)
  2. Go down the zipper measurement (mine is 15cm) plus 1.5cm (in my case the fly is 16.5cm long)

 

Step 2 - The Back

Now we’re going to shape the shape of the back pattern:

  1. Copy the back pattern piece and make sure to add the hip, crotch, knee and crease lines
  2. Divide the block into two panels by using the crease line
    • Transfer the dart to the left until it touches the crease line
    • At the crotch line go inwards 1.25cm on each side of the crease line
    • Create a curve from the crease line at the hip line, to the 1.25cm point to the knee line

 

Next step is adding the flare to the leg-lines

  1. Draw a horizontal line 1.25cm below the ankle line
  2. Draw a horizontal line 4cm below the ankle line
  3. Mark a point on the 1.25cm line 4cm, away from each edge of the ankle line
  4. Mark a point on the 4cm line, 4cm away from the crease line on each side
  5. Create a curve from one point to the other one
  6. Draw the flare from the knee line to the edges of the curve

Step 3 - The Waistband

This design has a curved waistband and we’re going to draw it by lowering the waistline and connecting the pieces together.

  1. Define how big you want the waistband (in my case 4cm) and lower it on your design
  2. Separate the pieces and connect them together (CB, side back, side front and CF). They should create a rough curve
  3. Smooth the curve
  4. Add 4cm to the centre front of the waistband. This is to account for the fly and the shield

 

We drew the waistband to be cut on the fold so the 4cm extension only needs to be cut on one of the sides (the one that has the shield attached)

Step 4 - The Pockets

This pair of trousers has two types of pockets, the ones at the front and the ones at the back. Let’s start with the ones at the front:

The front pockets are hidden in the seams, so we’ll use the side front panel to shape them. The pockets will have 4 parts: the side front, the pocket facing, and the two linings.

  • Side front: lower the side front panel 7cm
  • Facing: this is from the waistline to 13cm down (so 6cm below the new side front)
  • Lining top: this goes from the waistline to 22cm down (this is for a 15cm pocket and is perfect to fit your phone)
  • Lining bottom: this goes from the lowered side front to 15cm down

 

The back pocket is a bit less complicated to draft:

  1. Draw a square of 15x15cm
  2. Reduce the bottom part of the square to be 10cm (make sure it’s centered)
  3. Lower the “square” 2cm and shape the pocket like the one in the drawing

 

Here is some guidance on how to place the pocket. Have in mind this assumes the waistline to sit on the natural waist:

  1. Mark 10cm down at CB
  2. Mark 5.5cm down at side back
  3. Connect these two points. Align the top of the pocket with this line. It does not really matter where it’s placed horizontally

Step 5 - The Finishes

One last piece you’re going to need to make these pants is the shield that goes into the fly construction. For it, create a rectangle that is as long as your zipper plus 2.5cm and 8cm wide

Step 6 - The Hem (Optional)

The trousers I made did not have a bottom hem, but I will give you some guidance on how to add it. There are two options:

  • Option 1: Add 2cm seam allowances like we did for the other patterns. Take into account that you’re working with a curve and it will be trickier than normal to sew them
  • Option 2: Add a facing
    • Decide how big you want the hem to be. I would advice you to make it at least 2cm long, otherwise I would go for option 1.
    • Mark the 2cm on the lower part of the pattern pieces (like done for the green pieces in the image on the right)
    • Separate those pieces and they will be the facing. When sewing, attach them together like you would for the front and back panels and finally sew them to the bottom of the pants

Step 7 - The Seam Allowances

And just like that, the pattern is ready! The only thing left to do is adding the seam allowances. For this pattern I didn’t add a hem at the bottom of the pants because it was easier and I liked the look. If you want to add a hem, I would advise you to do a facing as it is going to be easier to control.

  1. Add 1cm seam allowances everywhere (except for the fly, the centre back of the waistband and the top of the back pocket)
  2. The fly has no seam allowance
  3. The centre back of the waistband has no seam allowance as it’s cut in the fold
  4. The top part of the back pocket has 2cm (3/4in) seam allowance because it’s folded twice

 

And just like that, your trousers are ready! I hope you enjoyed this Free Flared Trousers Sewing Pattern.

 

If you liked these instructions and are looking for more foundations and ways to modify them, you can check out my ebook on how to draft trousers.

There you have ALL the information you need to draft any trousers designs you’ve ever dreamed of. 

The ebook breaks down a pattern into:

  • The foundation: how to take measurements, draft them and fix any fitting issues
  • The Waistline: Instructions on how to change the waistline and how to add waistbands
  • The Length: I show you the modify the length to most typical ones
  • The Leg-line: Learn how to create leg-line designs like slim, tapered, straight or flared
  • The Details: Here you’ll find any design detail like yokes, pleats, turn ups, openings and many pocket designs 
  • The Finishes: Finally, learn how to finish up the pattern, add seam allowances, hems and all the important information

 

All in one place, check it out now!

Learn how to draft your dream trousers - eBook

€ 35,00

If you need a more step by step tutorial plus sewing instructions, here you have a video explaining all that:

Still curious? Here’s more